Which correctly lists butane ${\text{(}}{M_{\text{r}}} = {\text{58)}}$, propanone ${\text{(}}{M_{\text{r}}} = {\text{58)}}$, propan-1-ol ${\text{(}}{M_{\text{r}}} = {\text{60)}}$ and propan-2-ol

${\text{(}}{M_{\text{r}}} = {\text{60)}}$ in order of increasing boiling point?

A.     ${{\text{C}}_{\text{4}}}{{\text{H}}_{{\text{10}}}} < {\text{C}}{{\text{H}}_{\text{3}}}{\text{COC}}{{\text{H}}_{\text{3}}} < {\text{C}}{{\text{H}}_{\text{3}}}{\text{CH(OH)C}}{{\text{H}}_{\text{3}}} < {\text{C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{OH}}$

B.     ${\text{C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{OH}} < {\text{C}}{{\text{H}}_{\text{3}}}{\text{CH(OH)C}}{{\text{H}}_{\text{3}}} < {\text{C}}{{\text{H}}_{\text{3}}}{\text{COC}}{{\text{H}}_{\text{3}}} < {{\text{C}}_{\text{4}}}{{\text{H}}_{{\text{10}}}}$

C.     ${{\text{C}}_{\text{4}}}{{\text{H}}_{{\text{10}}}} < {\text{C}}{{\text{H}}_{\text{3}}}{\text{CH(OH)C}}{{\text{H}}_{\text{3}}} < {\text{C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{OH}} < {\text{C}}{{\text{H}}_{\text{3}}}{\text{COC}}{{\text{H}}_{\text{3}}}$

D.     ${{\text{C}}_{\text{4}}}{{\text{H}}_{{\text{10}}}} < {\text{C}}{{\text{H}}_{\text{3}}}{\text{COC}}{{\text{H}}_{\text{3}}} < {\text{C}}{{\text{H}}_{\text{3}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{C}}{{\text{H}}_{\text{2}}}{\text{OH}} < {\text{C}}{{\text{H}}_{\text{3}}}{\text{CH(OH)C}}{{\text{H}}_{\text{3}}}$

A

Most candidates were able to dismiss B and C but getting the correct answer required them to transfer their knowledge of steric hindrance (or alkane branching) to a different situation. 54% gave the correct answer whilst 30% gave D.