The compound formed by the reaction of ethanal with semicarbazide contains $.....................$ number of nitrogen atoms.

The given reaction is: $R_2C=O + HCN \rightarrow R_2C(OH)CN$

Formaldehyde when treated with $KOH$ gives methanol and potassium formate. The reaction is known as

The same product $(A)$ is formed in both of the following reactions:
$1. PhMgBr + CH_3-CN \xrightarrow{H_3O^{+}} (A)$
$2. Ph-COOH \xrightarrow{(1) \text{ excess } CH_3Li, (2) H_3O^{+}} (A)$
Identify product $(A)$.

An ester $(A)$ with molecular formula $C_9H_{10}O_2$ was treated with excess of $CH_3MgBr$ and the complex so formed was treated with $H_2SO_4$ to give an olefin $(B)$. Ozonolysis of $(B)$ gave a ketone with molecular formula $C_8H_8O$ which shows positive iodoform test. The structure of $(A)$ is

The product of the reaction between ammonia and formaldehyde is