3.92 g of ferrous ammonium sulphate crystals are dissolved in 100 ml of water, 20 ml of this solution requires 18 ml of $K M n O_{4}$ during titration for complete oxidation. The weight of ${KMnO}_{4}$ present in one litre of the solution is

see full answer

Talk to JEE/NEET 2025 Toppers - Learn What Actually Works!

Real Strategies. Real People. Real Success Stories - Just 1 call away

An Intiative by Sri Chaitanya

3.476 g

12.38 g

34.76 g

1.238 g

answer is A.

(Unlock A.I Detailed Solution for FREE)

Ready to Test Your Skills?

Check your Performance Today with our Free Mock Test used by Toppers!

Take Free Test

Detailed Solution

${MnO}_{4}^{-} + 5 {Fe}^{+ 2} + 8 H^{+} \to {Mn}^{+ 2} + 5 {Fe}^{+ 3} + 4 H_{2} O$

$\begin{array}{l} {KMnO}_{4} = Mohr salt \\ \frac{M_{1} V_{1}}{1} = \frac{M_{2} V_{2}}{5} \\ M_{1} V_{1} = [\frac{W}{Mol . wt \times V} \times 1000] \times \frac{V_{2}}{5} \\ [\frac{W \times 1000}{158 \times 1000}] \times 18 = \frac{3 .92 \times 1000}{392 \times 100} \times \frac{20}{5} \Rightarrow W = 3 .476 g \end{array}$