JEE Main · 2020 · 03 Sep 2020 · Shift 2 · Some Basic Concepts of Chemistry

The strengths of 5.6 volume hydrogen peroxide (of density

1 g / mL

) in terms of mass percentage and molarity (M), respectively, are:
(Take molar mass of hydrogen peroxide as

34 g / mol

)

Answer: (C)

Solution

A "5.6 volume" hydrogen peroxide liberates

5.6 L

of oxygen at STP per litre of solution, and volume strength relates to molarity by (volume strength)

= 11.2 M

, so

M = \frac{5.6}{11.2} = 0.5 M

. For the mass percentage,

M = \frac{10 \times ( % w / w ) \times d}{molar mass}

, so with

d = 1 g mL^{- 1}

and molar mass

34

0.5 = \frac{10 \times ( % w / w )}{34}

gives

% w / w = 1.7

. The strengths are

1.7%

and

0.5 M

JEE Main · 2020 · 03 Sep 2020 · Shift 2 · Single correct option