Question

ch3 ho — ch2
ch — o — c — o — ch2 — ch3
ch3 ch2 — o — ch3
o hemiacetal
o acetal
o neither
ho oh oh
ho
o hemiacetal
o acetal
o neither

Explanation:

A hemiacetal has a carbon atom bonded to one - OR group and one - OH group along with two other carbon - containing groups. An acetal has a carbon atom bonded to two - OR groups and two other carbon - containing groups. Analyze the structures based on these definitions.
For the first structure, there are multiple - OR groups and no - OH group directly attached to the key carbon atoms, so it is neither a hemiacetal nor an acetal.
For the second structure, there is a carbon atom bonded to one - OH group and multiple - OR groups, so it is a hemiacetal.

Answer:

First structure: neither
Second structure: hemiacetal