20.0 mL of a dilute hydrogen peroxide solution is titrated in acidic medium and requires 16.0 mL of 0.0500 M $KMnO X_{4}$ . The concentration of $H X_{2} O X_{2}$ (molar mass 34) in g per litre is:

Answer: D

mmol

MnO X_{4} X^{-}

= 0.8;

2 MnO X_{4} X^{-} + 5 H X_{2} O X_{2}

gives mmol

H X_{2} O X_{2}

0.8 \times 2.5 = 2.0

. Molarity = 2.0/20.0 = 0.100 M, so concentration =

0.100 \times 34 = 3.4

g/L.