Acetaldehyde reacts with $C_2H_5MgCl$. The final product is

Which of these reagents would accomplish the following reduction?
$NC-CH_2-CO-CH_2-CH=CH_2 \to NC-CH_2-CH(OH)-CH_2-CH=CH_2$

How many compounds among the following give white crystals when reacted with sodium bisulphite $(NaHSO_3)$?
$1. HCHO$
$2. CH_3CHO$
$3. CH_3COCH_3$
$4. C_6H_5COCH_3$
$5. C_6H_5COC_6H_5$

The product of the above reaction is

$(A)$ $\xrightarrow{NH_2OH} (B)$ $\xrightarrow{H_2SO_4} (C)$ $\xrightarrow{H_3O^{\oplus}} (D) + (E)$ $\xrightarrow{CHCl_3, KOH} CH_3-NC$ (carbylamine test). $(D)$ $\xrightarrow{SOCl_2} (F)$ $\xrightarrow{(i) PhMgBr \text{ (excess) } (ii) H^{\oplus}} (G)$ $\xrightarrow[\Delta]{H^{\oplus}} (H)$ $\xrightarrow{CH_2I_2, Zn/Cu} \text{1,1-diphenylcyclopropane}$. The molecular weight of compound $(A)$ is:

Which of the following is called as Mandelonitrile?