Benzalacetone is the product of mixed aldol condensation between benzaldehyde $(C_6H_5CHO)$ and acetone $(CH_3COCH_3)$. What is its structure?

Which of the following sequence of reagents converts $3-$hexene to propane?

Calcium butanoate on heating followed by treatment with $1,2-$ethanediol in the presence of a catalytic amount of an acid,produces a major product which is

Identify the product $(A)$ and the name of the reaction for the given transformation:

The correct option for the above reaction is

When liquid $A$ is treated with a freshly prepared ammoniacal silver nitrate solution,it gives a bright silver mirror. The liquid forms a white crystalline solid on treatment with sodium hydrogensulphite. Liquid $B$ also forms a white crystalline solid with sodium hydrogensulphite but it does not give a test with ammoniacal silver nitrate. Which of the two liquids is an aldehyde? Write the chemical equations of these reactions also.