What will be $X$ and $Y$ in the following reaction?

Wolff-Kishner reduction reduces which of the following groups?

The haloform test is given by which of the following substances?

An optically active compound $C_6H_{12}O$ gives a positive test with $2,4-$dinitrophenylhydrazine,but a negative test with Tollens' reagent. What is the structure of the compound?

Identify the reagents used for the following conversion:

When ethanal $(CH_3CHO)$ and propanal $(CH_3CH_2CHO)$ undergo cross-aldol condensation with dilute $NaOH$, the pair of products obtained by cross-condensation reaction is: