Chemistry Question on Aldehydes, Ketones and Carboxylic Acids

Question

Ketones react with $Mg - Hg$ over water gives :

Answer 1

Solution

Ketones on reduction with magnesium amalgum and water form pinacols undefined Ketones upon reaction with Grignard regent from tertiary-alcohol. Formaldehyde with Grignard reagent forms primary alcohol, acetaldehyde with Grignard reagent forms secondary alcohol. $2^{\circ}$ alcohol (except formaldehyde which form $1^{\circ}$ alcohol).