Question

Methyl acetylene on ozonolysis gives
(a)Acetaldehyde
(b)Acetone
(c)Gloxal
(d)Methyl glyoxal

Answer 1

Hint: Ozonolysis is an organic reaction where the unsaturated bonds of alkenes, alkynes, or azo compounds are cleaved with ozone. Alkenes and alkynes form organic compounds in which the multiple carbon–carbon bond has been replaced by a carbonyl group while azo compounds form nitrosamines.

Complete answer:
Methyl acetylene on ozonolysis gives acetaldehyde. Therefore, option A is the correct option. The reaction is written below.

In ozonolysis reaction the formation of intermediate also takes place which is ozonoid. The short method or short trick to learn this reaction is that you have to break the double and triple bond and place the hydrogen with each molecule after breaking the bonds. When the ozonoid is formed this reaction proceeds further in the presence of $Zn$ and $H_{2}O$ to form the desired product. In the above reaction, the products formed are acetaldehyde $\left(C_2{H}_{4}O\right)$ and formaldehyde $\left(HCHO\right)$. When only ozonolysis of acetylene takes place, the product formed is glyoxal.
Hence the correct answer is option C.

Note:
Ozonolysis is an organic reaction in which the unsaturated bonds of alkenes, alkynes, and azo compounds get broken or cleaved by ozone. In the ozonolysis reaction of alkenes and alkynes formation of organic compounds takes place. In this reaction carbon-carbon multiple bonds have been replaced by the carbonyl group whereas in the ozonolysis of azo compounds, formation of nitrosamines takes place. The outcome just depends on the bonds being oxidized.