Question

Which of the following do not contain an acyl group?
(A) Acid chloride
(B) Amide
(C) Ester
(D) Ether

Answer 1

Hint: To answer this question, we first need to understand what acyl group is. An acyl group is a moiety formed from an oxoacid, including inorganic acids, by removing one or more hydroxyl groups. It has an alkyl group and a double-bonded oxygen atom. The acyl group is commonly produced from a carboxylic acid in organic chemistry.

Complete answer:
Acid chloride - An acyl chloride is an organic molecule having the functional group -COCl in organic chemistry. Their formula is generally represented as RCOCl, with R standing for side chain. They are carboxylic acid reactive derivatives. Acetyl chloride is an example of an acyl chloride.
Amide - A chemical having the generic formula RCNR′R′′, where R, R', and R′′ denote chemical groups or hydrogen atoms, is known as an amide, sometimes known as an organic amide or a carboxamide in organic chemistry.
Ester - As in the substitution reaction of a carboxylic acid and an alcohol, an ester is a chemical molecule produced from an acid in which at least one –OH hydroxyl group is replaced by a –O– alkyl group.
Ether - Ethers are organic compounds with an ether group, which is an oxygen atom bonded to two alkyl or aryl groups. They have the general formula R–O–R′, with R and R′ denoting alkyl or aryl groups, respectively.
RCOCl stands for acid chloride, RCONH for amide, RCOOR for ester, and ROR for ether.
RCO is the formula for the acyl group. As a result, ether does not have an acyl group.
So, the final answer is option (D) i.e., Ether.

Note:
A functional group is a substituent or moiety in a molecule that produces the molecule's distinctive chemical reactions in organic chemistry. Regardless of the remainder of the molecule's composition, the same functional group will undergo the same or similar chemical processes.