Question

20 volume $H_2{O}_2$ solution has a strength of about

• A. 30%
• B. 6%
• C. 3%
• D. 10%

Answer 1

Answer: (B)

20 volumes of $H_2{O}_2$ means 20 litres of oxygen is obtained at STP by the decomposition of 1 litre $H_2{O}_2$ solution $2H_2{O}_2\to 2H_{2}O+O_2$ 2 mole 1 mole 68 g 22.4 litre at STP 22.4 litres oxygen is obtained from 68 g $H_2{O}_2$ $\therefore$ 20 litres oxygen is obtained from = $\frac{68}{22.4}\times 20=60.7g{H}_2{O}_2$ $\therefore$ 1000 ml of $H_2{O}_2$ solution contains 60.7 g $H_2{O}_2$ 100 ml (= 100 g) solution contains = $\frac{60.7}{1000}\times 100$ $\therefore$ Strength of $H_2{O}_2$ solution = 6.07. g $H_2{O}_2$ = 6.07%