Molar volume at STP is 22.4 L/mol. '20 volume' H2O2 releases 20 L of O2 at STP per litre on decomposition (2H2O2 -> 2H2O + O2). Find the volume (in mL, two decimals) of 0.1 M acidified KMnO4 required to oxidise 10 mL of this solution.

JEE Main levelNumerical answerDifficulty 2 of 3rx134

Molar volume at STP is $22.4 L/mol$ . '20 volume' $H X_{2} O X_{2}$ releases $20 L$ of $O X_{2}$ at STP per litre on decomposition ( $2 H X_{2} O X_{2} 2 H X_{2} O + O X_{2}$ ). Find the volume (in mL, two decimals) of $0.1 M$ acidified $KMnO X_{4}$ required to oxidise $10 mL$ of this solution.

Numerical answer type, answer in mL, tolerance 0.05.

n (O X_{2}) = 20/22.4

per litre, so

[H X_{2} O X_{2}] = 2 \times 20/22.4 = 1.7857 M

. Meq of

H X_{2} O X_{2}

= 10 \times 1.7857 \times 2 = 35.714

N (KMnO X_{4}) = 0.5

, so

V = 35.714/0.5 = 71.43 mL