Question

Addition of water to acetylene in presence of suitable catalyst produces:

• A. acetaldehyde
• B. acetone
• C. ethyl alcohol
• D. acetic acid

Answer 1

Answer: (A)

acetaldehyde

$C_2{H}_2+H_{2}O+H^{+}\to C{H}_{2}CHOH\to C{H}_{3}CHO$
Addition of water to acetylene in the presence of an acid gives an enol i.e ethenol or vinyl alcohol in this case which is then rearranged to form a carnonyl group, in case of non-terminal alkynes, ketones are formed and in case of terminal alkynes like acetylene aldehydes are formed i.e acetaldehyde.