Question

$25 \,mL$ of $0.50\, M \,H_{2}O_{2}$ solution is added to $50\, mL\, of\, 0.20\, M \,KMnO_{4}$ in acid solution. Which of the following statements is true?

• A. $0.010$ mole of oxygen is liberated
• B. $0.005$ mole of $KMnO_{4}$ are left
• C. $0.030$ g atom of oxygen gas is evolved
• D. $0.0025$ mole $H_{2}O_{2}$ does not react with $KMnO_{4}$

Answer 1

Answer: (B)

M eq. of $KMnO_{4} = .2 \times 50 \times 5 = 50$
M eq. of $H_{2}O_{2} = 2 \times 25 \times .5 = 25$
M eq. of $KMnO_{4}$ remaining $= (50 - 25) = 25$
Mole of $KMnO_{4} =\frac{25}{5} \times 10^{-3} =5 \times 10^{-3} =.005$