What is the IUPAC name of the following molecule?
Which compound has the highest melting point?
What is the correct IUPAC name of the following compound?
Which of the following alkanes will have the lowest boiling point?
What is the parent name for the following alkane?
(Note: The parent name corresponds to the longest continuous chain of carbon atoms.)
For the following two pairs of molecules, identify which partner will have the higher boiling point.
|A)||Pair 1: A; Pair 2: C|
|B)||Pair 1: B; Pair 2: D|
|C)||Pair 1: A; Pair 2: D|
|D)||Pair 1: B; Pair 2: C|
How many isomers are there of C6H14?
How many isomers are there of C5H11Cl?
How many isomers are there of dimethylcyclopentane (neglecting enantiomers)?
How many isomers are there of dimethylcyclopropane (neglecting enantiomers)?
How many isomers are there of dimethylcyclohexane (neglecting enantiomers)?
Which Newman projection does NOT represent the following compound?
Which Newman projection has two gauche interactions?
What are the total number of conformers (staggered and eclipsed) that you can draw for the following molecule?
A “gauche” interaction costs 3.8 kJ/mol, a hydrogen–hydrogen eclipsing interaction costs 4.0 kJ/mol, a hydrogen–methyl eclipsing interaction costs 6.0 kJ/mol, and a methyl–methyl eclipsing interaction costs 11 kJ/mol.
What is the relative energy cost of the MOST stable conformer of 2,3-dimethylbutane?
Which of the following statements about conformations is FALSE?
|A)||Conformers can be isolated and separated at room temperature.|
|B)||Conformers are interconverted by rotation about sigma bonds.|
|C)||For butane the staggered anti conformation is the most stable.|
|D)||For ethane the eclipsed conformation is the least stable.|
Choose the correct Newman projection for 2-methylpentane.
Which of the following is the MOST stable cycloalkane per CH2?
Which of the following cycloalkanes has the MOST strain energy?
A medium sized ring such as cyclooctane is less stable than cyclohexane. Which of the following statements describes cyclooctane?
|A)||It is planar and has an internal bond angle of 135°.|
|B)||It is puckered and has a bond angle of 109°.|
|C)||It has 16 pairs of eclipsed H–H steric interactions.|
|D)||The heat of combustion per CH2 group is less than that for cyclohexane.|
Place the following structures properly on the (abbreviated) energy surface for cyclohexane ring reversal.
|A)||1 = b or c, 2 = a, 3 = d, 4 = b or c|
|B)||1 = d, 2 = b or c, 3 = d, 4 = a|
|C)||1 = d, 2 = b or c, 3 = a|
|D)||1 = b or c, 2 = d 3 = a, 4 = b or c|
Which of the following cyclohexane conformations has the MOST energy (is the LEAST stable)?
The boat conformation has how many eclipsing H–H interactions?
Which of the following statements regarding cyclohexanes is FALSE?
|A)||A cyclohexane ring never exists in a boat conformation.|
|B)||A chair conformation of cyclohexane has no torsional strain.|
|C)||A chair conformation of cyclohexane has no angle strain.|
|D)||At equilibrium, 99% of the cyclohexane molecules are in a chair conformation.|
Which of the following molecules is trans-1, 2-dimethylcyclohexane?
The equilibrium constant equals 1 for the interconversion of the two chair conformations of a dimethylcyclohexane when the methyl groups are in which positions?
|A)||both are equatorial|
|B)||both are axial|
|C)||one is axial and the other is equatorial|
|D)||both are pseudo-equatorial|
How many gauche/diaxial interactions are present in cis-1,2-dimethylcyclohexane?
|A)||1 gauche and 2 diaxial interactions|
|B)||2 gauche and 1 diaxial interactions|
|C)||1 gauche and 1 diaxial interactions|
|D)||2 gauche and 2 diaxial interactions|
Which of the following dimethylcyclohexane isomers have chair conformations that are mirror images?
The balanced equation for the combustion of pentane is
|A)||4 C5H12 + 2 O2 → 20 CH4 + 4 H2O|
|B)||2 C3H8 + O2 → 3 CH4 + 2 H2O|
|C)||C5H12 + 8 O2 → 5 CO2 + 6 H2O|
|D)||C3H8 + 5 O2 → 3 CO2 + 4 H2O|
Which of the following statements is NOT correct regarding the reactivity of alkanes?
|A)||Alkanes are generally inert.|
|B)||Alkanes are often used as solvents for chemical reactions.|
|C)||Alkanes react with acids and bases.|
|D)||Alkanes react with halogens and oxygen upon ignition.|
Which of the following is NOT a source of strain in “boat” cyclohexane?
|C)||“flagpole” or “bowsprit” interaction|