Question

What will be the mass of oxygen liberated by decomposition of 200 mL hydrogen peroxide solution with a strength of 34 g per litre?

• A. $25.5g$
• B. $3.0g$
• C. $3.2g$
• D. $4.2$g

Answer 1

Answer: (C)

$3.2g$

Answer 2

: Strength of the solution = 34 g/L

1 L of The solution contains34 g of $H_{2}O_{2}$

200 mL of the solution contains $\frac{34}{100} \times 200 = 6.8g$

$\underset{2 \times 34g}{2H_{2}O_{2}} \rightarrow 2H_{2}O + \underset{32g}{O_{2}}$

68 g of $H_{2}O_{2}$gives 32 g $O_{2}$

$6.8$g of $H_{2}O_{2}$gives $= \frac{32}{68} \times 6.8 = 3.2g$of $O_{2}$