In the given reaction sequence: $HOOC-CH_2-CH_2-COOH$ $\xrightarrow{\Delta} (A)$ $\xrightarrow{CH_3-CH_2-NH_2/\Delta} (B)$. $(B)$ will be:

Saponification (basic hydrolysis) of $C_6H_5-CO-^{18}OCH_3$ will yield. [$^{18}O$ = mass $-18$ isotope of oxygen]

Consider the following reaction:
$\text{Propanal} + \text{Methanal}$ $\xrightarrow[\text{(ii)}\Delta, \text{(iii)}\text{NaCN}, \text{(iv)}\text{H}_3\text{O}^+]{\text{(i)}\text{dil. NaOH}} \text{Product } B (C_5H_8O_3)$
The correct statement for product $B$ is:

What is the ratio of $(x/y)$ in the above reactions?

An ester $(A)$ with molecular formula $C_9H_{10}O_2$ is reacted with an excess of $CH_3MgBr$. The resulting product is treated with concentrated $H_2SO_4$ to form an olefin $(B)$. Ozonolysis of $(B)$ yields a ketone with the formula $C_8H_8O$. What is the structure of $(A)$?

Which of the following pairs of compounds can be differentiated by $NaHCO_3$ as well as by $NaOH$?