Problems and exercisesAlkanes and Cycloalkanes

1. 2-Methylbutane

For 2-methylbutane, (CH₃)₂CHCH₂CH₃:

1. Write its molecular formula and that of its other two isomers.
2. Classify its carbons as primary, secondary and tertiary.
3. Will it boil at a higher or lower temperature than pentane? Why?
4. Balance its complete combustion.

2. Its chlorination

The reactivity of hydrogens towards chlorine is primary : secondary : tertiary = 1 : 4 : 5. Calculate the proportions of the four monochlorinated derivatives of 2-methylbutane.

3. Conformations

Looking along the C2–C3 bond of 2-methylbutane, how many gauche methyl–methyl interactions do its staggered conformations have?

4. Methylcyclohexane

Which chair of methylcyclohexane is the most stable? What is the energy difference and what causes it?