Question

what is the common name of ch3(ch2)2 - o - (ch2)2ch3?
propyl propyl ether
dipropyl ether
dibutyl ether
butyl butyl ether
butyl propyl ether

Explanation:

The structure $CH_3(CH_2)_2 - O-(CH_2)_2CH_3$ has two propyl ($CH_3CH_2CH_2-$) groups attached to the oxygen atom. In common - naming of ethers, when two identical alkyl groups are present, we use the prefix 'di -' followed by the name of the alkyl group and then 'ether'. So, it is dipropyl ether.

Answer:

B. dipropyl ether