An organic compound $B$ is formed by the reaction of ethylmagnesium iodide $(CH_3CH_2MgI)$ with a substance $A,$ followed by treatment with dilute aqueous acid. Compound $B$ does not react with $PCC$ in dichloromethane. Identify $A$.

Write down functional isomers of a carbonyl compound with molecular formula $C_3H_6O$. Which isomer will react faster with $HCN$ and why? Explain the mechanism of the reaction also. Will the reaction lead to the completion with the conversion of whole reactant into product at reaction conditions? If a strong acid is added to the reaction mixture what will be the effect on concentration of the product and why?

Identify the alcohol obtained when an aldehyde other than formaldehyde $(HCHO)$ is treated with Grignard's reagent $(RMgX)$ followed by hydrolysis.

Consider the following sequence of reactions.
$C_6H_5COONa$ $\xrightarrow[\Delta]{NaOH/CaO} X$ $\xrightarrow[\text{Anhy. } AlCl_3]{CO/HCl} Y$ $\xrightarrow[NaOH]{\text{conc. }} A + B$.
If $A$ is the reduction product of $Y$,what is $B$?

The alkaline $CuSO_4$ solution containing sodium potassium tartrate does not react with:

The product $(B)$ in the given reaction is: