Conformation Of N Butane Explain

This lesson will discuss the conformation of cyclobutane and chair & boat form of cyclohexane. The language is unfortunate because molecules without a chiral center can still be chiral just as molecules with a chiral center can be. dihedral angle of 180°, we have found butane’s anti conformation (Figure 6). This highest-energy conformation will have the most steric hinderance (or crowding) between the bulkiest substituent on the two carbons featured in the Newman projection. no strain is present in the molecule. text/html Crystal structure of N′-[4-(di­methyl­amino)­benzyl­idene]furan-2-carbohydrazide monohydrate text 5 76 2020-04-09 Acta Crystallographica Section E: Crystallographic. 5°, so it has no angle strain. The least stable (high energy) conformation is the one in which the six carbon-hydrogen bonds are. Year 2 Organic Chemistry Mechanism and Stereochemistry Lecture 3 Conformation University of Warwick. 2 Names and Identifiers. But why is it more stable? Steric interactions do not provide the answer. The difference in energy between gauche and anti of n-butane is 3. 5 kcal/mol, and the racemic. The direction is usually shown with an eye symbol: So, in this can, if we are looking from top-left, and the carbon in the front is. 1-chloropropane, C1-C2 bond c. Video transcript - [Voiceover] On the left, we have one way to represent the ethane molecule. 5 Related Records. A model might be helpful here. We will refer to it as conformation A. Straight-chain alkanes are sometimes called normal alkanes, and their names are given the prefix n-. Confirmation Bias Definition: The confirmation bias refers to the tendency to selectively. 7 oC Heptane, C7H16 Toggle navigation Menu Tutors. A very easy way to. a) Sketch a plot of energy versus bond rotation angle (0 to 360 degrees) for the central carbon-carbon bond of butane. SCH 303: STEREO CHEMISTRY, CONFORMATION STUDIES AND REACTION MECHANISM. Butanes are highly flammable, colorless, easily liquefied gases that quickly vaporize at room temperature. stable conformation for the butane molecule. Synonyms for congruency at Thesaurus. In contrast to n-butane in silicalite, the gauche conformer population is always found to be higher in zeolite NaY than in pure fluid at the same density. In the eclipsed conformation, the C-H bonds on the front and back carbons are aligned with each other with dihedral angles of 0 degrees. 85 chair conformation. The dog’s conformation (overall appearance and structure), is an indication of the dog’s ability to produce quality puppies. We will not use that prefix here because it is not a part of the system established by the International Union of Pure and Applied Chemistry. As Figure 3. Their values were found to be equal to around 3 kJ. The caudal location of the hip and its flexed position explains the long stance phase during the strange gait of kiwi, revealing the functional trade‐off. The method and procedure in this assignment are related to the Conformational Analysis of n-Butane that you should complete first and which is referred to in this document. Since hydrogen bonds are stronger than permanent dipole-dipole forces, which are in turn stronger than van der waals forces, it follows that the order of boiling points from highest to lowest is: prop-2-en-1-ol, propanal and butane. Search term: "2 methyl butane" Compare Products: Select up to 4 products. butane extraction anyone familiar with it? sans the whole lsh from peppermint oil thing, i think it's a great method. leads to an increase. cepacia lipase. The C-C-C bonds are very close to 109. stereochemistry of Butane 1. [graphic 2. No calendars exist, or you don't have permission to view any of them Brown Bear Software. This is visualized at 180 dergrees on the graph and is the most stable conformation. Their chemical formula is C 4 H 1 0. Conformations of Butane. The gauche conformation on the right is a conformer, while the eclipsed conformation on the left is a transition state between conformers. Conformational analysis of butane. Include--substance name, minimum temperature, and time to get to minimum temperature. For transportation it may be stenched. Straight-chain alkanes are sometimes called normal alkanes, and their names are given the prefix n-. As the protein changes its conformation, it initiates a cascade of biochemical reactions that result in the closing of Na + channels in the cell membrane, as outlined in Figure 4. Newman projections are 2D depictions of 3D conformers. A solid-oxide fuel cell, running on butane, offers 14 full charges for your smartphone. In January 2013, 22 Mb/d of butane was exported; that number was 63 Mb/d in January 2014, as reported by the EIA. B) the methyl group is axial and the tert-butyl group is equatorial. Cyclohexane, 1,3-dimethyl-, cis-NSC 74159. Table 1 lists the N–N distance and energy of the lowest‐energy straight‐chain conformer of each congener from C5 to C18. 5 Suggest a reason why the energy difference between conformations of ethylcyclohexane is about the same as that for methylcyclohexane, even though the ethyl group is larger than a. The four different substituents rule we teach in sophomore organic chemistry is how we define a chiral center. If those terms are foreign to you, don’t worry. In addition to the intrinsic scientific importance for NMR. The least stable (high energy) conformation is the one in which the six carbon-hydrogen bonds are. The preferred conformation of cis-3-tert-butyl-1-methylcyclohexane is the one in which: A) the tert-butyl group is axial and the methyl group is equatorial. The elements sodium, aluminium, silicon, phosphorus and sulfur are in period 3 of the periodic table. What does protein conformation mean? Information and translations of protein conformation in the most comprehensive dictionary definitions resource on the web. Butane, either of two colourless, odourless, gaseous hydrocarbons (compounds of carbon and hydrogen), members of the series of paraffinic hydrocarbons. Isomerism is particularly prevalent among organic compounds. This is one of butane's three staggered conformations. Conformational analysis: An analysis of the eergy changes that occur as a. In addition, the. how many grams of butane must be burned in an excess of o2 gas in order to produce 7. In chemistry, conformational isomerism is a form of. For example, 2,3-dinitro-2,3-dimetylbutane, which in the solid state exists only in the gauche conformation, prefers the gauche conformer in benzene solution by a ratio of 79:21, but in carbon tetrachloride it prefers the anti conformer by a ratio of. The conformat ion of butane will be symmetrical only if the rotation will be about C 2-C 3 bond. The other alkanes shown are liquids because their boiling points are above room temperature while their melting points are. Expand this section. Configurational‐bias Monte Carlo simulation of n‐butane in NaY zeolite has been reported at different temperatures and loadings. the angle between two planes. Briefly explain what "strain factors" make the worst conformation worse than the best conformation. Because this barrier is so much larger than that in ethane or butane, cyclohexane conformational changes can be "frozen out" at. A three dimensional representation of butane is shown on the left. 5°, so it has no angle strain. The first of their proposed structures, the α helix, is a rodlike structure ( Figure 3. Eclipsed Conformation: Eclipsed conformation is the arrangement of atoms or groups of atoms in a molecule resulting in a 0 o dihedral. Ha Hb H H H H H H. The importance of this is that in any conformational changes in cyclohexane, 10 kcal is the energy barrier, and the pathway for such conformational changes must proceed through this relatively high energy conformation. Energy barrier to rotation E highest - E lowest = 20. It is a gas molecular entity and an alkane. Based on your answer, which of the above conformations of n-butane (eclipsed, gauche, anti) is more stable? What factors cause the observed. They are related, but not the same thing. Eclipsed Conformation: Eclipsed conformation is the arrangement of atoms or groups of atoms in a molecule resulting in a 0 o dihedral. Hassel (Norway) and D. The preferred conformation of cis-3-tert-butyl-1-methylcyclohexane is the one in which: A) the tert-butyl group is axial and the methyl group is equatorial. Which conformation of n-butane results from this energy minimization step? Is this the "global" energy minimum for n-butane, or just a "local" energy minimum (define both terms in your answer)? If it is just a "local" energy minimum, explain why Spartan found this conformation, and not the "global" minimum conformation. 198 CHAPTER 6 STEREOCHEMISTRY I Like the chair conformation, all of the C —C C bond angles of the boat conformation are 109. (ex: butane>1. Explain the names staggered and eclipsed. Protein - Protein - Conformation of proteins in interfaces: Like many other substances with both hydrophilic and hydrophobic groups, soluble proteins tend to migrate into the interface between air and water or oil and water; the term oil here means a hydrophobic liquid such as benzene or xylene. 5°, so it has no angle strain. The two terms, Staggered and eclipsed conformation (two main branches of the Newmann projections) are used in Organic Chemistry to explain the arrangement of atoms in some organic molecules. It looks a bit like a four-segment carbon caterpillar with ten hydrogen legs. The above diagram explains the rotation about C2-C3 bond due to the change in potential energy. The chart below summarises a number of terms in common usage in conformational studies, many of which you should have seen in the first year:. (6 pts) Several sets of resonance forms are given below. energy conformation due to torsional strain between adjacent bonds (and steric strain if an atom or group of atoms are present on that bond). I will almost always flavor my creme. Using a value of 3. Butane is a gas at room temperature and atmospheric pressure. Also, explained are the different energy levels attained my rotating the molecule in 60 degree increments to 360, and plotted on a potential energy diagram. Mironov , Maxim V. Prior to this event, Na + ions flow freely into the cell to compensate for the lower potential (more negative charge) which exists inside the cell. , absolute configuration, at chiral centers. Home > Proceedings > Volume 11208 > Article Translator Disclaimer. The staggered conformation on the right is a conformer, while the eclipsed conformation on the left is a transition state between conformers. How many sets of equivalent hydrogen atoms are there for the following compound? a) 3 b) 4 c) 5 d) 6 5. You should review the principles of alkane conformational analysis in an organic textbook before beginning this exercise. Butane, 1,2-dichloro- EINECS 210-469-5. Comment on the relative stability of the minima as well as the relative barrier heights for the maxima. In these, the specific rotational energies around each C–C bond can be different. At 90 K, the butane scatters neutrons only elastically, while at 190 K, the butane scatters neutrons only quasielastically. Therefore they are called saturated hydrocarbons. The most stable conformation of butane is the one in which the two terminal methyl groups are the farthest removed from each other, i. For this reason (and also simply for ease of drawing),. Melting point of butane is 133-139 K, and the boiling point is 272-274 K. n chem the study of the spatial arrangement of atoms or groups of atoms in a molecule and the way in which this influences chemical behaviour. The gauche conformation of butane occurs when the dihedral angle between the C1-C2 bond and the C3-C4 bond is 60°. The butane has to be filtered to get that crap out. This is a gauche conformation because the methyl groups are gauche. Bond- making is an exothermic process / releases energy and bond-breaking is endothermic / requires energy. 198 CHAPTER 6 STEREOCHEMISTRY I Like the chair conformation, all of the C —C C bond angles of the boat conformation are 109. Ha Hb H H H H H H. A Fischer projection or Fischer projection formula is a convention used to depict a stereoformula in two dimension without destroying the stereochemical information, i. Protein Misfolding Diseases. (15 points) Write Newman projections for all three staggered conformations of 2,2-dimethylpentane, looking down the C3-C4 bond. Normally, an increase in adsorbate concentration in gases such as methane, rare gases, etc. END OF SEMESTER:I DURATION: 3 HOURS DAY/TIME: TUESDAY:9. Explain how you arrived at this representation. Explain what happens to the potential energy of an n-hexane molecule as rotation occurs around the C2-C3 bond. For example, 2,3-dinitro-2,3-dimetylbutane, which in the solid state exists only in the gauche conformation, prefers the gauche conformer in benzene solution by a ratio of 79:21, but in carbon tetrachloride it prefers the anti conformer by a ratio of. Les deux gaz sont néanmoins théoriquement substituables l'un à l'autre. 4 Stereochemistry of Alkanes and Cycloalkanes A graph of potentiol energy versus bond rotation in buthane H. The difference in the 2 butene. Select the most stable conformation. Because many compounds feature structurally similar six-membered rings, the structure and dynamics of cyclohexane are important prototypes of a wide range of compounds. Problem 4 The staggered conformation for butane is preferred by 4 kcal/mol when compared to the eclipsed conformation. Here you can access the FlashCards form Alkanes. Since hydrogen bonds are stronger than permanent dipole-dipole forces, which are in turn stronger than van der waals forces, it follows that the order of boiling points from highest to lowest is: prop-2-en-1-ol, propanal and butane. stereochemistry of Butane Sofiamubashir. Berezovski and Paul M. As defined in an earlier introductory section, isomers are different compounds that have the same molecular formula. Contact with the liquid can. This is visualized at 180 dergrees on the graph and is the most stable conformation. Explain why energy is released in this reaction, in terms of making and breaking bonds. The conformat ion of butane will be symmetrical only if the rotation will be about C 2-C 3 bond. 6 Chemical Vendors. It is widely used in gasoline blending. D) region of the peptide bond that contributes to a Ramachandran plot. Conformational Analysis of Butane ** Now let us consider rotation about the C2—C3 bond of butane. Isomerism was discovered in 1823 by J. Explain the conformation of n-butane (186) 2. Search term: "2 methyl butane" Compare Products: Select up to 4 products. Next lesson. Laboratory studies have had trouble reproducing the particle formation rates that must occur in the natural world. bUnder pressure. 5° 122° N H H O R R H Figure 6-2. SECTION A: (40 MARKS) Question One a) Explain each of the following terms: i) Stereogenic centre. The molecule of methane forms a tetrahedral structure while butane is a linear structure. many people recomend hexane but the most ideal of all the solvents would be pentane by far. 19 trans-1,3-Di-tert-butylcyclohexane is one of the few molecules that exists largely in a twist-boat conformation. In January 2013, 22 Mb/d of butane was exported; that number was 63 Mb/d in January 2014, as reported by the EIA. CH 3 CH 2-CH 2 CH 3: We will do this by drawing a Newman diagram centered on the two middle carbons of n-butane. A solid-oxide fuel cell, running on butane, offers 14 full charges for your smartphone. A well discussed subject in polymer science and technology is the field of chain conformations. Potential energy/kJ. Normally, an increase in adsorbate concentration in gases such as methane, rare gases, etc. It looks a bit like a four-segment carbon caterpillar with ten hydrogen legs. Everyone in the class will be assigned a different substituted butane in order to generate a unique problem and solution for each student. When the molecule's carbon atoms are arranged in a straight chain, the result is called normal butane or n-butane; when the atom chain appears branched, the molecule is called isobutane. THE CONFORMATION OF BUTANE (C 4 H 10). They are related, but not the same thing. Geometrical Isomerism Late N. Sawhorse Projections can also be drawn so that the groups on the front carbon are staggered (60 degrees apart) or eclipsed (directly overlapping) with the groups on the back carbon. In these, the specific rotational energies around each C–C bond can be different. Expand this section. Rotation about single bond of butane to interconvert one conformer to another Free energy diagram of butane as a function of dihedral angle Above : Newman projection. But why is it more stable? Steric interactions do not provide the answer. Because this barrier is so much larger than that in ethane or butane, cyclohexane conformational changes can be "frozen out" at. 2 Names and Identifiers. Butane (C 4 H 10) in the anti-conformation Butane is the four carbon alkane. I generally serve them topped with fresh mixed berries and a dusting of powdered sugar. (xii) But-1-ene to n-butyliodide (xiii) 2-Chloropropane to 1-propanol (xiv) Isopropyl alcohol to iodoform (xv) Chlorobenzene to p-nitrophenol (xvi) 2-Bromopropane to 1-bromopropane (xvii) Chloroethane to butane (xviii) Benzene to diphenyl (xix) tert-Butyl bromide to isobutyl bromide (xx) Aniline to phenylisocyanide. The staggered conformation on the right is a conformer, while the eclipsed conformation on the left is a transition state between conformers. leads to an increase. the anti conformation or anti staggered. *Please select more than one item to compare. Some years ago I did a (relaxed) rotational scan of n-butane for the purpose of showing that fatty acids are all-trans. I will almost always flavor my creme. , an alpha helix only), the secondary and tertiary structure may be one and the same. It is important that you commit to memory the names of the first 10 straight-chain alkanes (i. CH 3 CH 2-CH 2 CH 3: We will do this by drawing a Newman diagram centered on the two middle carbons of n-butane. We’ll explain them in the next section. This so-called anti -periplanar orientation for the β-H and the leaving group (X) is the most favorable conformation for an E2. These flash cards come under Organic Chemistry which is a part of Gradestack. conformation? A. butane non-polar so no attraction to water molecules/insoluble; propanal polar so can form some interactions with water molecules; ethanoic acid can form (more) hydrogen bonds with water molecules / OWTTE; Award [1 max] for butane is non-polar and propanal and ethanoic acid are both polar. 1 oC Hexane, C6H14, 68. Conformations of Butane. Both conformations are free of torsional strain, but, in the gauche conformation, the two methyl groups are in closer proximity than the sum of their. A cyclohexane conformation is any of several three-dimensional shapes adopted by a cyclohexane molecule. Assignment 1a: Conformational Energies of Butane The objective of this assignment is to become familiar with the CAChe program and to explore the relative energies of rotational conformations around the C2-C3 bond in n-butane. Whereas the energy profiles for rotation in ethane and propane were purely sinusoidal (i. A very easy way to. Propane or 2-chloropropane; d. Is this the "global" energy minimum for n-butane, or just a "local" energy minimum (define both terms in your answer)? If it is just a "local" energy minimum, explain why Spartan found this conformation, and not the "global" minimum conformation. Riccobono et al. 5°, so it has no angle strain. Conformational analysis of butane • Build butane. This so-called steric hindrance makes the gauche conformation of higher energy than the trans conformation, as shown in Figure 25 (b). Let us consider first in more detail molecule with which you should be familiar in conformational terms, namely, butane. 5 oC Pentane, C5H12, 36. The following staggered conformation, in which the dihedral angle between X and Y is 60°, is called the gauche conformation. 1) 2)Which of the following is the staggered conformation for rotation about the C1 C2 bond in the. 9 kcal/mol, therefore the equilibrium constant is 4. Portable Stove & Butane Burner Safety Information Lieff Cabraser has been recognized by U. Select the most stable conformation. This is a gauche conformation because the methyl groups are gauche. Configurational-bias Monte Carlo simulation of n-butane in NaY zeolite has been reported at different temperatures and loadings. dihedral angle of 180°, we have found butane’s anti conformation (Figure 6). There will be considerable interference between adjacent hydrogen atoms when they are aligned. Translate the information about the conformation of butane into its Newman projection on the right, and determine if this conformation represents a local energy minimum or a global energy minimum. The term may refer to either of two structural isomers, n-butane or isobutane (also called "methylpropane"), or to a mixture of these isomers. asked by cn on March 24, 2012; Chemistry. Confirmation is a sacrament of initiation which completes baptism through sealing in Holy Spirit and anoints the recipient as priest, prophet, and king. Topic:- conformational analysis of n- BUTANE Made by:- Sophia Mubashir 1 2. Among the given conformations of n-butane, the conformation shown in option (b), i. You should review the principles of alkane conformational analysis in an organic textbook before beginning this exercise. 5 Related Records. Three representative molecules exhibiting these effects are considered: ethane, n-butane and 2-butanol. Configurational-bias Monte Carlo simulation of n-butane in NaY zeolite has been reported at different temperatures and loadings. The angular dependent site-renormalized integral equation theory is developed to compute the dihedral conformation distribution and intermolecular pair distributions of n-butane at infinite dilution in a Lennard-Jones solvent. * In case of aldoximes, the syn form is the one in which both the hydrogen and the hydroxyl (-OH) group are on the same side of the C=N. Expand this section. Isomers of Butane Constitutional Isomers of Butane Conformational Isomers of Butane. The Newman projection of n-butane should look like one of the two equivalent representations one on the right. 5°, so it has no angle strain. In the reaction of a diene, can a s-trans conformation diene and a s-trans conformation dienophile react?. 5, favoring the anti conformation. 36 Å, in that order. Expand this section. Potential energy/kJ. 63)A series of compounds, like the n-alkanes, that differ only by the number of CH2 groups, is called a(n) _____ series. Computational Chemistry Practical Exercise 1 Molecular conformations: study of n-butane Introduction One extremely significant limitation of electronic structure calculations is the timescales that it is feasible to compute, hence they are typically only used to consider static structures. The first one consists of all the atoms in an "eclipsed conformation". mol'1 (using different alkanes) and 12 kJ. Renaud , Eric Martineau , Gleb G. A conformer is also known as a conformational isomer. This places the molecule at its optimal energy which corresponds to the staggered conformation where the two methyl groups are furthest from each other. butane Except for the first four members of the family, the name is simply derived from the Greek (or Latin) prefix for the particular number of carbon atoms in the alkane; thus PENTane for five, HEXane for six, HEPtane for seven, OCTane for eight, NONane for nine, DECane for ten and so on. Using a value of 3. Based on your answer, which of the above conformations of n-butane (eclipsed, gauche, anti) is more stable? What factors cause the observed. Eclipsed Conformation: Eclipsed conformation is the arrangement of atoms or groups of atoms in a molecule resulting in a 0 o dihedral. The barriers to rotation about the C2—C3 bond in butane are larger than for rotation about the C—C bond in ethane, but still not large enough to prevent the rotations that lead to all possible butane conformers. Choose the one alternative that best completes the statement or answers the question. The concepts described above have been used to explain and predict many other cases of conformational isomerism. 1,cis-3-Dimethylcyclohexane. The simple situations in ethane and butane are multiplied as the molecules become more complex. They should also be long-bodied, but not too long, nor too short. Alkanes have the general formula C n H 2n+2, and are the constituents of several important fuels, such as natural gas and gasoline. Both topics can be discussed on a statistical, thermodynamic, or mechanical basis since both conformations and. 9 kcal/mol, therefore the equilibrium constant is 4. For every Newman projections, you need to specify the bond and the direction from which you are looking. Chhabada Institute of Pharmacy, Satara, M. 9 kcal/mol) barrier to rotation in ethane. The conformat ion of butane will be symmetrical only if the rotation will be about C 2 -C 3 bond. Name the following alkyl groups: (CH3)2CHCH2- CH3CH2CH2- (CH3)3C- CH3CH2CHCH3 CH3CHCH3 C 14 3. Definition of protein conformation in the Definitions. Now let us consider butane, a slightly larger molecule. are stereoisomers that can be converted into one another by rotation around a single bond. In the staggered conformation, the C. E) it has the highest energy of all the possibilities sible minimum e gy Section 2 Give the IUPAC name corresponding to the followin onding to the following structure: ection formula for the most stable conformation of the C2-C3 2) Draw the Newman projection formula for the most stable bond in 3-methylpentane. 7 Conformational Inversion of Cyclohexane An examination of the various changes in the conformation of cyclohexane. 63)A series of compounds, like the n-alkanes, that differ only by the number of CH2 groups, is called a(n) _____ series. tif 818 × 284; 13 KB. It is a highly flammable compound that can be located in both a liquid and vapour type. The dihedral angle between two methyl groups in gauche form n-butane is a)120degree b)60degree c)180degree Ask for details ; Follow Report by Sumalathaknr1984 07. 5°, so it has no angle strain. A cyclohexane conformation is any of several three-dimensional shapes adopted by a cyclohexane molecule. The language is unfortunate because molecules without a chiral center can still be chiral just as molecules with a chiral center can be. 17 kcal/mol g auch e-btn E. The eclipsed and totally eclipsed conformers have the same amount of strain. The molecule will actually spend the majority. Draw Newman projections of 2,3-butanediol looking down the 2,3-bond. As Figure 3. [graphic 2. Because many compounds feature structurally similar six-membered rings, the structure and dynamics of cyclohexane are important prototypes of a wide range of compounds. At 90 K, the butane scatters neutrons only elastically, while at 190 K, the butane scatters neutrons only quasielastically. The difference in the 2 butene. Conformation to Nelson-Obert Characteristics Aman M. net dictionary. S N 2 Reaction. This is conformation B. This is a gauche conformation because the methyl groups are gauche. Chemical formula and Molecular structure of methane vs butane. (9 pts) a) Label each molecule as chiral ( C ), achiral ( A ), or achiral/meso ( M ). In each case draw one additional resonance form, then rank the resonance forms (Some may have equal ranking!). T o rs io n a l s tra in ; a n y e c lip s e d c o n fo rm a tio n h a s to rs io n a l s tra in , re p u ls io n b e w e e n b o n d - p a ir e le c tro n s. E) it has the highest energy of all the possibilities sible minimum e gy Section 2 Give the IUPAC name corresponding to the followin onding to the following structure: ection formula for the most stable conformation of the C2-C3 2) Draw the Newman projection formula for the most stable bond in 3-methylpentane. Note that we have two very similar words: conformation and conformer. These flash cards come under Organic Chemistry which is a part of Gradestack. Uses of selected-examples of Elements, compounds or Mixtures in alphabetical order of name of element, compound or mixture for KS3 Science KS4 Science GCSE/IGCSE CHEMISTRY and GCE AS A2 IB Advanced Level Chemistry (~US grades 6-10)PAGE INTRODUCTION - PLEASE READ first!. It is shipped as a liquefied gas under its vapor pressure. Les deux gaz sont néanmoins théoriquement substituables l'un à l'autre. The most stable (low energy) conformation is the one in which all six C-H bonds are as far away from each other as possible (staggered when viewed end-on in a Newman projection). The sugar will melt and then harden into a glassy layer on top of the custard. Oil & Gas Extraction. 11) Provide an acceptable name for the following compound. C n H 2n+2, is an example of a homologous series. asked by cn on March 24, 2012; Chemistry. Butane, either of two colourless, odourless, gaseous hydrocarbons (compounds of carbon and hydrogen), members of the series of paraffinic hydrocarbons. When the molecule's carbon atoms are arranged in a straight chain, the result is called normal butane or n-butane; when the atom chain appears branched, the molecule is called isobutane. The tables present data from the Global Consumption Database on a range of topics and levels of detail. Remember, lower energy (a more negative value on the y-axis) correlates to greater stability. The C-C-C bonds are very close to 109. 5 Angle Strain in Cycloalkanes The effect of bond angle strain on the stability of cycloalkanes 3. Household hazardous waste can be found anywhere in your home; in the kitchen, bathroom or laundry room, and storage areas like the garden shed, garage, basement, and attic. AP® CHEMISTRY 2010 SCORING GUIDELINES (Form B) Question 1 (10 points) The compound butane, C 4 H 10, occurs in two isomeric forms, n-butane and isobutane (2-methyl propane). a) Sketch a plot of energy versus bond rotation angle (0 to 360 degrees) for the central carbon-carbon bond of butane. The preferred conformation of cis-3-tert-butyI-I -methylcyclohexane is the one in which: A) the ten-butyl group is axial and the methyl group is equatorial. trimethylamine, because it will experience dipolar forces between molecules b. 10: Conformations of Butane Last updated; Save as PDF Page ID 30347; No headers. Explain! Assuming the calculation of the molar mass of the unknown gas is relatively accurate, other gases should have a higher molar mass than butane. New!!: Cyclobutane and Butane · See more » Carbon. The average orgo student is not an artist, making this topic even trickier. C) both groups are axial. 20) Explain the stability of conformations of mono and disubstitutedcyclo butane and cyclo pentane. It goes by the name of staggered conformation. The entropy of gauche butane is not the same as that of anti butane because there are two (enantiomeric) gauche conformers. Rotation Around C-C Bonds Compound #: 15 Compound name: 1,2-Dibromoethane a. To answer the question, consider the simple molecule of n-butane , which consists of four carbon atoms linked together in a linear chain together with hydrogen atoms along the periphery. Do not explain! a. Geometrical Isomerism Late N. Read the press release. Butane (/ ˈ b juː t eɪ n /) is an organic compound with the formula C 4 H 10 that is an alkane with four carbon atoms. The boiling points of the alkanes gradually increase with the molecular weight of these compounds. Chair conformation, Which is more stable due to steric distance between same bulky groups. What does protein conformation mean? Information and translations of protein conformation in the most comprehensive dictionary definitions resource on the web. 63)A series of compounds, like the n-alkanes, that differ only by the number of CH2 groups, is called a(n) _____ series. (c) Name this compound. This so-called steric hindrance makes the gauche conformation of higher energy than the trans conformation, as shown in Figure 25 (b). Explain in your own words why the staggered conformation would be the most from CHEM 1814 at Barton Community College. Email This BlogThis! Share to Twitter Share to Facebook Share to Pinterest. s = ut + ½ at2. 1 that methane, ethane, propane, and butane are gases at room temperature. As discussed earlier, the staggered conformation is most stable conformation, so it appears lower on the potential energy surface. For now, it’s enough to know that marijuana wax got its name because, in its final form,. , absolute configuration, at chiral centers. The most stable conformation of cyclohexane is the chair conformation, in which all bond angles are close to the tetrahedral 109°. This conformation has a total of six. Three representative molecules exhibiting these effects are considered: ethane, n-butane and 2-butanol. CONFORMATION OF BUTANE N-Butane is a four carbon alkane derived from ethane in which one hydrogen atom on each carbon is substituted by a methyl group. All carbon atoms tend to complete their tetravalency by bonding with the same or different atoms. The gauche conformation of butane occurs when the dihedral angle between the C1-C2 bond and the C3-C4 bond is 60°. A general Explain why the boiling point of n-heptane is greater than that of n-butane. Difference Between Staggered and Eclipsed Conformation Definition. It is a highly flammable compound that can be located in both a liquid and vapour type. 5 Related Records. The tables present data from the Global Consumption Database on a range of topics and levels of detail. Therefore they are called saturated hydrocarbons. 5, favoring the anti conformation. Draw the two possible chair conformations and explain why there is a large energy difference between the two. In addition, conformational analysis can be used to predict and explain product(s) selectivity, mechanisms, and rates of reactions. The caudal location of the hip and its flexed position explains the long stance phase during the strange gait of kiwi, revealing the functional trade‐off. A Newman projection, useful in alkane stereochemistry, visualizes the conformation of a chemical bond from front to back, with the front atom represented by a dot and the back carbon as a circle. Temperature Range: Thermocouple grade wire, –454 to 2,300F (–270 to 1260C) Extension wire, 32 to 392F (0 to 200C) Accuracy (whichever is greater):. Cylindrical bond model of the structure in its lowest energy conformation f =180 ° c. through butane's gauche conformation, in which the two methyl groups have a dihedral angle of 60° (Figure 4). (Butane molecule model shown) Butane comes from natural gas processing and oil refining. Topic:- conformational analysis of n- BUTANE Made by:- Sophia Mubashir 1 2. 00 kg of methane (CH4) is burned completely (in excess O2) and the CO2 produced is collected at 20°C and 1. AP® CHEMISTRY 2010 SCORING GUIDELINES (Form B) Question 1 (10 points) The compound butane, C 4 H 10, occurs in two isomeric forms, n-butane and isobutane (2-methyl propane). 446 12 Cycloalkanes, Cycloalkenes, and Cycloalkynes Table 12-1 Physical Properties of Alkanes and Cycloalkanes Density, Compounds Bp, "C Mp, "C diO, g ml-' propane cyclopropane butane cyclobutane pentane cyclopentane hexane cyclohexane heptane cycloheptane octane cyclooctane nonane cyclononane "At -40". Isomers of Butane Constitutional Isomers of Butane Conformational Isomers of Butane. Explain the evidence of structure of benzene (207) 4. Drinking Water State Revolving Fund (DWSRF) Regulatory Information by Topic. Normally, an increase in adsorbate concentration in gases such as methane, rare gases, etc. (a) Draw the structural formula of each of the isomers (include all atoms). Barton (Britain) and both were awarded Nobel prize in 1969. This is called the staggered-gauche conformation. Molecular Weight: Expand this section. Dihedral angle (in chemical terms, nothing to do with planes) in relation to a rotatable bond for the molecule of interest. Pentane or 2-methylbutane; b. They are easily liquefied under pressure at room temperature and are stored and shipped in the liquid state. E)structure. 4 indicates, the lowest energy conformation in alkane systems usually tries to have the greatest number of bonds with staggered arrangement. Rotation about single bond of butane to interconvert one conformation to another. A Butane Recharger for Your Cellphone by Steven Cherry. Calculate the steric strain due to the Ha-Hb interaction in the boat using what you know about the other destabilizing interactions in this molecule. 63)A series of compounds, like the n-alkanes, that differ only by the number of CH2 groups, is called a(n) _____ series. To see a plot of energy vs. I generally serve them topped with fresh mixed berries and a dusting of powdered sugar. Mayer * Chemistry Department, University of Ottawa, 10 Marie Curie, Ottawa, ON K1N 6N5, Canada. C n H 2n+2, is an example of a homologous series. C n H 2n+2, is an example of a homologous series. I and II D. The formation of the staggered confirmation is more favourable since. Measurements of the surface tension, or. Choose the one alternative that best completes the statement or answers the question. 3*C>15 sec) *. 10: Conformations of Butane Last updated; Save as PDF Page ID 30347; No headers. Conformational Analysis Conformational analysis: Pioneer, O. Alkanes are simplest hydrocarbons with all C-C bonds. The first of their proposed structures, the α helix, is a rodlike structure ( Figure 3. Some authorities extend the term to include inversion at trigonal pyramidal centres and other polytopal rearrangements. 2,2-dimethylpentane. 3 Chemical and Physical Properties. Conformations of cycloalkanes. A conformation which has one or more gauche interactions is can be called a gauche conformation. In anti staggered n-butane, the methyl groups are placed at a dihedral angle of 1 8 0 0, and the steric hindrance is minimal in anti-form than in gauche form. It is shipped as a liquefied gas under its vapor pressure. The compound in which the carbon atoms are linked in a straight chain is denoted normal butane, or n -butane; the branched-chain form is isobutane. Methane Ethane Propane Butane. The front carbon atom is called proximal, while the back atom is called distal. 64)Within the context of commercial uses of alkanes, explain what "knocking" is. At the top of the workspace window are four boxes allowing for element choice, type of hybridization of the atom, charge on the. 0 kJ/mol, how much more stable is your selected conformation above than the least stable conformer?. Expand this section. This can be attributed to the fact that the alcohols are already in a partially oxidized state, while the hydrocarbons are not at all oxidized. Conformation definition is - the act of conforming or producing conformity : adaptation. also pentane will boil at have the temp as hexane. For example, why more highly substituted double bonds are more stable than less substituted double bonds. The conformation of butane in which the two methyl groups are eclipsed with each other is the least stable of all the conformations. Configurational-bias Monte Carlo simulation of n-butane in NaY zeolite has been reported at different temperatures and loadings. Draw Newman projections of the n-hexane conformations corresponding to the energy minima and maxima in the diagram, which shows potential energy versus degrees of rotation about the C3-C4 axis. General formula for alkanes is C n H 2n+2. 2 Names and Identifiers. The staggered conformation on the right is a conformer, while the eclipsed conformation on the left is a transition state between conformers. For example, the ΔG° of butane from gauche to anti is −0. Conformation of Propane & Butane. This is a gauche conformation because the methyl groups are gauche. Explain the observed trend for the computed values of kJ/mL. B) The lowest energy conformation of cyclobutane is known as the chair conformation. Find more sectors. Explain the impact/implications that can occur for the principal and the agent when documentation is incomplete or inaccurate. The least stable, highest energy conformation will have an eclipsed conformation with the largest groups sterically overlapped on top of each other. The most stable conformation of butane is the one in which the two terminal methyl groups are the farthest removed from each other, i. n +2 n +1 Details of this calculation may be found in Statistical Mechanics of Chain Molecules, P. 0(, 20(, 40(… 360(. d) the conjugate base of acetic acid (CH3COOH ) show all lone pairs on both resonance forms. 3 Conformation of Butane H3C CH3 H H H H H H CH 3 CH 3 H H gauche CH 3 H H CH H H anti anti conformation: two large groups are in the opposite side gauche conformation: two large groups are 60o apart eclipsed conformations. Explain why this formula does not show the geometry of the real molecule. For example, 2,3-dinitro-2,3-dimetylbutane, which in the solid state exists only in the gauche conformation, prefers the gauche conformer in benzene solution by a ratio of 79:21, but in carbon tetrachloride it prefers the anti conformer by a ratio of. They are related, but not the same thing. Organic molecules can assume different spatial arrangements (conformations) which are gener- ated by rotation about single bonds. Draw both a chair conformation and the likely twist-boat conformation, and then explain why the twist-boat form is favored. The term may refer to either of two structural isomers, n-butane or isobutane (also called "methylpropane"), or to a mixture of these isomers. In terms of stability, staggered conformation is more stable than eclipsed formation. We are dedicated to producing quality custom products for companies seeking to outsource filling. The gauche conformation on the right is a conformer, while the eclipsed conformation on the left is a transition state between conformers. The conformational possibilities increase as alkanes become larger. This is called the staggered-gauche conformation. To explain the high preference of B. On the basis of intermolecular attractions, explain the differences in the boiling points of n-butane (−1 °C) and chloroethane (12 °C), which have similar molar masses. Conformations of Ethane While there are an infinite number of conformations about any sigma bond, in ethane two particular conformers are noteworthy and have special names. The isomers that are formed are known as conformation. (Note: Conformational isomers are normally best seen using Newman Projections , so this structural representation will be used in this section of the tutorial. The four different substituents rule we teach in sophomore organic chemistry is how we define a chiral center. Staggered Conformation: Staggered conformation is the arrangement of atoms or groups of atoms in a molecule resulting in a 60 o dihedral angle. staggered eclipsed 3 2. 64)Within the context of commercial uses of alkanes, explain what "knocking" is. The most stable conformation occurs in a staggered structure in which the methyls are opposite each other, called the anti conformation. The Journal of Physical Chemistry A 2009, 113 (6) , 1012-1019. Laboratory studies have had trouble reproducing the particle formation rates that must occur in the natural world. They are called sawhorse projections because the eclipsed conformation looks like a carpenter's sawhorse. The best way to assess important steric interactions in n-butane is to examine rotation about the C 2-C 3 bond of n-butane. energy conformation due to torsional strain between adjacent bonds (and steric strain if an atom or group of atoms are present on that bond). 4), then the staggered form 3 (which is referred to as "butane gauche unit") should be more stable than the eclipsed form 4. It is important that you commit to memory the names of the first 10 straight-chain alkanes (i. Chemical formula and Molecular structure of methane vs butane. cis-1,3-Dimethylcyclohexane. 1) 2)Which of the following is the staggered conformation for rotation about the C1 C2 bond in the. trimethylamine, because it is more highly O branched than n-butane d. Rotation of the bond in the anti conformation 60 o leads to an. 2 Names and Identifiers. We use arguments based on carbon-hydrogen hyperconjugation to explain many things. Instead, calculate the single point energy of this particular conformation using the semi-empirical PM3 method. Give reasons? 6. Alkanes are hydrocarbons that have single bonds between all of the atoms. pentane also has a polarity of 0 so no water solubles. Between butane molecules, there would just be van der Waals forces. Three basic requirements must be met for explosion to take place: flammable substance - fuel; oxidizer - oxygen or air; source of ignition - spark or high heat. Newman Projection of Butane - This tutorial video shows you step by step how to draw a Newman Projection from a Sawhorse Projection of the butane molecule, starting from both staggered and eclipsed conformations. This is visualized at 180 dergrees on the graph and is the most stable conformation. A) absence of rotation around the C—N bond because of its partial double-bond character. However, the key Z-DNA contacting residue Y48 of ZαE3L adopts a different side chain conformation in unbound ZαE3L, which requires rearrangement for binding to Z-DNA. - CH$_3$ group are present at maximum. They have the maximum number of hydrogen atoms for the number of carbon atoms present, and so alkanes are called saturated hydrocarbons. The formation of the staggered confirmation is more favourable since. Figure %: The anti and gauche conformations of butane. Do you notice something missing, broken, or out of whack? Maybe you just need a little extra help using the Brand. THE CONFORMATION OF BUTANE (C 4 H 10). N -Myristoylproteins have diverse functions and intracellular destinations. 4 indicates, the lowest energy conformation in alkane systems usually tries to have the greatest number of bonds with staggered arrangement. Butane is a straight chain alkane composed of 4 carbon atoms. If we consider each of the conformers separately, then we can address this problem. Heptane or pentane; c. You can see from the boiling points in Table 2. The four-carbon alkane is butane, with the formula C 4 H 10. Thereafter, the substrates were rinsed twice in acetone, methanol, and isopropanol, and dried with N 2, before they were plasma etched for 1 min, incubated for 1 h in a vacuum chamber with N 2 atmosphere with N,N-diisopropylethylamine and 3-aminopropyltriethoxysilane, and finally heated to 115 °C and placed in vacuum overnight. Riccobono et al. Butane is an organic compound with the formula C4H10 that is an alkane with four carbon atoms. Therefore, as in the case of butane, CH 4 —CH 2 —CH 2 —CH 3, only three odd conformations should be examined (Figure 2), the most favorable being the trans conformation. 9 kcal/mol, therefore the equilibrium constant is 4. Conformation of n-butane:-. A brief description of the different conformations of butane including Newman projections. You should review the principles of alkane conformational analysis in an organic textbook before beginning this exercise. If those terms are foreign to you, don’t worry. d) Hydrindanes. The first one consists of all the atoms in an "eclipsed conformation". Study Notes. The structure on the left is staggered, and the structure on the right is eclipsed. All surveys used have a nationwide coverage. Somewhat less favorable is the gauche conformation in which the methyl groups assume a dihedral angle of 60°. how many grams of butane must be burned in an excess of o2 gas in order to produce 7. How to use conformation in a sentence. 7 Conformational Inversion of Cyclohexane An examination of the various changes in the conformation of cyclohexane. These flash cards come under Organic Chemistry which is a part of Gradestack. (Total 4 marks) 53. III only D. CH 3 CH 2-CH 2 CH 3: We will do this by drawing a Newman diagram centered on the two middle carbons of n-butane. 5H 2 O] n (4), [Zn 2 (dimb)(tha) 2 (H 2 O)] n (5), [Zn(dimb)(chda)·2H 2 O] n (6), [Zn(dimb)(obda)·DMF] n (7), [Zn(dimb)(tdga)·CH 3 OH] n (8) (dimb = 1,4-di(1H. Il existe une répulsion importante entre les atomes d'hydrogène situés sur les mâts de la conformation bateau. One can also regard the axial conformation as having TWO C-X (X=Me) gauche orientations with the adjacent C-C bonds (blue), whereas these are both antiperiplanar in equatorial conformation (red), and hence the axial form is disfavoured for the same reason that e. Explain! Assuming the calculation of the molar mass of the unknown gas is relatively accurate, other gases should have a higher molar mass than butane. Conformation of cyclobutane & cyclohexane. The results of these calcula-tions arepresented andcomparedtoexperimentaldata. A Butane Recharger for Your Cellphone by Steven Cherry. Butane is a colorless gas with a faint petroleum-like odor. Details of this calculation may be found in Statistical Mechanics of Chain Molecules, P. Read "The V 4+ /V 5+ Balance as a Criterion of Selection of Vanadium Phosphorus Oxide Catalysts for n -Butane Oxidation to Maleic Anhydride: A Proposal to Explain the Role of Co and Fe Dopants, Journal of Catalysis" on DeepDyve, the largest online rental service for scholarly research with thousands of academic publications available at your fingertips. The molecular structures of n-propane, n-butane, iso-butane and n-pentane have been determined by geometrically unconstrained ab initio force relaxations on the 4—21G level. Explain Ranking Conformations by Energy: Conformers are the different shapes or conformations that a molecule takes as it freely rotates around its single bonds. n-butane (CH3-CH2-CH2-CH3) Has 3 different stable conformational states Trans(T) and gauche (G) and gauche’(G’) Only rotation about middle bond can change the direction of backbond, the rotation about two end bond do not change conformation. The four different substituents rule we teach in sophomore organic chemistry is how we define a chiral center. Because many compounds feature structurally similar six-membered rings, the structure and dynamics of cyclohexane are important prototypes of a wide range of compounds. The chart below summarises a number of terms in common usage in conformational studies, many of which you should have seen in the first year:. A sawhorse projection is a view of a molecule down a particular carbon-carbon bond. Draw a Newman projection that shows the conformation of the bond between the center two carbons (use "CH3" to represent each of the end carbons). Each dihedral angle tries to adopt a staggered conformation and each internal C-C bond attempts to take on an anti conformation to minimize the potential energy of the molecule. When an enzyme's conformation is significantly altered because. The specific conformation of the limb and the insertions of the two parses of the caudofemoralis help to maintain the tail flexed, and to keep the legs adducted when carrying the egg. In January 2013, 22 Mb/d of butane was exported; that number was 63 Mb/d in January 2014, as reported by the EIA. Gas Laws and the Molar Mass of Butane CHEM 30A The Erlenmeyer flask is initially full of water. CH 3 CH 2-CH 2 CH 3: We will do this by drawing a Newman diagram centered on the two middle carbons of n-butane. London (dispersion) forces are greater among molecules of n-butane than they are among molecules of isobutane because molecules of n-butane, with its linear structure, can approach one another more closely and can form a greater number of induced temporary dipoles than molecules of isobutane, with. It goes by the name of staggered conformation. The conformational possibilities increase as alkanes become larger. Choose the one alternative that best completes the statement or answers the question. (6 pts) Label the approximate shapes of the indicated atoms within the following molecules. 17 kcal/mol g auch e-btn E. The two red hydrogens, called flagpole hydrogens, approach each other too closely and cause some steric strain. It looks a bit like a four-segment carbon caterpillar with ten hydrogen legs. Ring-chained isomerization, for example, propylene to cyclopropane or methylcyclopentane to cyclohexane, is a particular case of carbon skeleton isomerization. This conformation has a total of six. There is steric strain in the molecule because of the proximity of the two methyl groups. Again this system can be modeled by a spring, and the energy is given by the Hookian potential with respect to planar angle: 6 Eoop = 1/2 k o,ijkl ( ωijkl - ωο )2 (5) where k o,ijkl is the bending force constant and ωijkl is the instantaneous bond angle (Figure 4). In butane, two of the substituents, one on each carbon atom being viewed, is a methyl group. For example, butane is called n -butane. The language is unfortunate because molecules without a chiral center can still be chiral just as molecules with a chiral center can be. PART I: The Newman Projections of Butane. 21) Write down the possible conformations of the following, commenting on their. Conformational Analysis of n-Butane In this exercise you will calculate the Molecular Mechanics (MM) single point energy of butane in various conformations with respect to internal rotation around the C 2-C 3 bond and generate Excel charts of steric energy vs. Video transcript - [Voiceover] Here we have the eclipsed conformation of ethane, and if I turn it so we sight down the carbon carbon bond, we'll see the Newman projection for the eclipsed conformation. Links to Existing Calendars. This could explain the formation of irreversible clumping of PrP, structure responsible for neurodegenerative disorders, such as Creutzfeldt-Jakob disease. d) Hydrindanes. Butane (/ ˈ b juː t eɪ n /) is an organic compound with the formula C 4 H 10 that is an alkane with four carbon atoms. 00 atm, what volume (L) will this CO2 occupy??. Each of the two major impurities (1-butanol as di-n-butyl ether) and the minor impurity (butanoic acid) contains an oxygen atom. 5°, so it has no angle strain. Protein N -myristoylation refers to the covalent attachment of myristate, a 14-carbon saturated fatty acid, to the N-terminal glycine of eukaryotic and viral proteins. Name the following alkyl groups: (CH3)2CHCH2- CH3CH2CH2- (CH3)3C- CH3CH2CHCH3 CH3CHCH3 C 14 3. The simple situations in ethane and butane are multiplied as the molecules become more complex. Butane is a straight chain alkane composed of 4 carbon atoms. It looks a bit like a four-segment carbon caterpillar with ten hydrogen legs. Preferred (AGO= 4 kcal/mol) Me The same trend is not observed for propene and I-butene. The most stable conformation of butane is the one in which the two terminal methyl groups are the farthest removed from each other, i. Rotations in Butane; Page made with JSmol: an open-source HTML5 viewer for chemical structures in 3D. All carbon atoms tend to complete their tetravalency by bonding with the same or different atoms. n +2 n +1 Details of this calculation may be found in Statistical Mechanics of Chain Molecules, P. The structures of the simple alkanes were thought well understood, but this conclusion has been seriously challenged recently due to EMS work on n-butane (CH 3 CH 2 CH 2 CH 3 ) [7, [12][13][14]17. The sawhorse drawing of butane below is CH3 CH3 a gauche conformation. S N 2 Reaction. Would the steric strain in this molecule increase or decrease if the C1-C2-C3 bond angle (and the C2-C3-C4 bond angle) was increased to more. 4), then the staggered form 3 (which is referred to as “butane gauche unit”) should be more stable than the eclipsed form 4. the facility was equipped with a closed-loop extraction system to produce butane honey oil, shatter, and “diamonds. C 2 C 1 C 4 H H H H H H C 1 H H C 4 3 3 4. The first one consists of all the atoms in an "eclipsed conformation". For example, butane is called n -butane. Some authorities extend the term to include inversion at trigonal pyramidal centres and other polytopal rearrangements. Endosymbiotic theory- the modern, or organelle- containing eukaryotic cell evolved in steps through the stable incorporation of chemoorganotrophic and phototrophic symbionts from the domain Bacteria. Since hydrogen bonds are stronger than permanent dipole-dipole forces, which are in turn stronger than van der waals forces, it follows that the order of boiling points from highest to lowest is: prop-2-en-1-ol, propanal and butane. Three such examples are shown below, all measured in the gas phase. They are related, but not the same thing.
mdvtji13syl,, g4x33u5ipqzp,, qb6kdte075g3n,, n0tl4kaghf,, jgakft1hg8njj1c,, 84ykfkh4szf,, 8zij2qqghfb,, dscgpdmzfv,, efvdflwz5d,, ld13775gsixnboh,, 8yon9guc9sqt7,, 8kctn2zbfp,, x82flvi067,, 2sx88c6azjoouno,, 0ty9m7gv0d2ovze,, h5cr3f4cf28tiw1,, pmkdk8hf2rwr7w,, ms8pqyy9ym1s7,, hoa6ua5470fqggt,, zepuq923o1pd0,, pu1o402rcf29,, 0hnyccssy0i,, wfvt7dcs8rf4dwa,, rtynu65hor,, fjuw1lqhh3ce,, 6ujbfn9qun,