Question 17

1. Identify product L: Starting from $m$-xylene ($C_8H_{10}$), Friedel-Crafts acylation followed by Finkelstein and $S_N2$ substitution with sodium 3-nitrophenolate yields $J$ ($C_{16}H_{15}NO_4$).

Reduction of the ketone to an alcohol followed by bromination gives $K$ ($C_{16}H_{16}BrNO_3$) with a molar mass of $350$ g/mol. $K$ reacts with excess $NH_3$ to replace $-Br$ with $-NH_2$, forming $L$ ($C_{16}H_{18}N_2O_3$).

The molar mass of $L$ is $192(C) + 18(H) + 28(N) + 48(O) = 286$ g/mol.

2. Kjeldahl's Method: In this method, only the nitrogen from the amine group ($-NH_2$) is converted to $NH_3$. Nitrogen in the nitro group ($-NO_2$) is not estimated by this method.

3. Calculation: Moles of $L = \frac{5.72}{286} = 0.02$ mol. Since each molecule of $L$ provides $1$ estimated nitrogen atom, moles of $NH_3$ evolved = $0.02$ mol.

The neutralization reaction is: $2NH_3 + H_2SO_4 \rightarrow (NH_4)_2SO_4$.

Moles of $H_2SO_4$ required = $\frac{0.02}{2} = 0.01$ mol.

Volume of $1$ M $H_2SO_4 = \frac{0.01 \text{ mol}}{1 \text{ mol/L}} = 0.01$ L = $10$ mL.