A 10.0 mL sample of H2O2 solution is added to excess acidified KI, and the iodine formed requires 30.0 mL of 0.100 M Na2S2O3. Which statements are correct (H2O2 = 34 g/mol; 2H2O2 -> 2H2O + O2; molar volume 22.4 L at STP)?

The iodine liberated is 1.50 mmol

The molarity of the H2O2 solution is 0.150 M

The concentration of H2O2 is 5.1 g/L

The iodine liberated is 1.50 mmol

The molarity of the H2O2 solution is 0.150 M

The volume strength of the solution at STP is 3.36

The concentration of H2O2 is 5.1 g/L

JEE Advanced levelOne or more correct optionsDifficulty 3 of 3eq165

A 10.0 mL sample of $H X_{2} O X_{2}$ solution is added to excess acidified KI, and the iodine formed requires 30.0 mL of 0.100 M $Na X_{2} S X_{2} O X_{3}$ . Which statements are correct (H2O2 = 34 g/mol; $2 H X_{2} O X_{2} 2 H X_{2} O + O X_{2}$ ; molar volume 22.4 L at STP)?

Thiosulfate = 0.100

\times

30.0 = 3.00 mmol, so

I X_{2}

= 1.50 mmol (true) and

H X_{2} O X_{2}

= 1.50 mmol in 10.0 mL = 0.150 M (true). Concentration = 0.150

\times

34 = 5.1 g/L (true). Volume strength = 0.150

\times

11.2 = 1.68 (1 mol

H X_{2} O X_{2}

gives 11.2 L

O X_{2}

), not 3.36 (false).