Exam

JEE Main

Year

2025

Date

3 April

Shift

Evening Shift

Subject

Chemistry

Chapter

Hydrocarbons

JEE Main 2025 · 3 April · Evening Shift · Chemistry · Hydrocarbons

X g of nitrobenzene on nitration gave 4.2 g of m-dinitrobenzene. X=...

X g of nitrobenzene on nitration gave 4.2 g of m-dinitrobenzene.
$\mathrm{X}=$______ g. (nearest integer)
[Given : molar mass (in $\mathrm{g} \mathrm{mol}^{-1}$) $\mathrm{C}: 12, \mathrm{H}: 1$, $\mathrm{O}: 16, \mathrm{~N}: 14]$

Step-by-step solution

$$\begin{array}{ll}\mathrm{C}_6\mathrm{H}_5\mathrm{NO}_2 & \mathrm{MF}=\mathrm{C}_6 \mathrm{H}_4 \mathrm{~N}_2\mathrm{O}_4 \\ \mathrm{MW}=123 & \mathrm{MW}=168 \\ & \therefore \frac{4.2}{168}=0.025 \mathrm{~mol}\end{array}$$
$\because$ required gm of nitro benzene
$$\begin{aligned}<br />& =123 \times 0.025 \\<br>& =3.075<br />\end{aligned}$$
$\therefore$ Nearest integer is 3$