Q23 / 180 · COMEDK 2019 · Chemistry
50 ec of oxalic acid is oxidised by 25 cc of $0.20 \mathrm{~N} \mathrm{KMnO}$. The mass of oxalic acid present in 500 ce of the solution is
- Correct answerA$3.15 \mathrm{~g}$
- B$31.5 \mathrm{~g}$
- C$6.3 \mathrm{~g}$
- D$63 \mathrm{~g}$
Solution
Equivalent moles of oxalic acid = Equivalent moles $=N_{1} V_{1}=25 \times 0.2 \times 10^{-3}=5 \times 10^{-3}=0.005$
$\frac{\text { Weight of oxalic acid }}{\text { Eq. weight of oxalic acid }}=0.005$
Weight of oxalic acid $=0.05 \times 63=0.315 \mathrm{~g}$ $\therefore 0.315 \mathrm{~g}$ in 50 ce of oxalic acid.
In 500 ce solution, mass of oxalic acid is
$$
=0.315 \times \frac{500}{50}=3.15 \mathrm{~g}
$$
Hence, the correct answer is option: 'A'.