Ncert Exercises & Solutions

Calculate the strength of 5 volumes H₂O₂ solution.

By definition, 5 volumes H₂O₂ solution means that 1 L of this H₂O₂ solution on decomposition produces 5 L of O₂ at STP.

2 H_{2} O_{2} \to 2 H_{2} O + O_{2}

2 \times 34 g \to 22.7 L at STP

If 22.7 L O₂ at STP will be obtained from

H_{2} O_{2} = 68 g

∴

5 L of O₂ at STP will be obtained from

H_{2} O_{2} = \frac{68 \times 5}{22.7} g = 14.98 = 15 g

∴

Strength of H₂O₂ in 5 volume H₂O₂ solution=

= 15 g L^{- 1}

\Rightarrow

Percentage strength of H₂O₂ solution

= \frac{15}{1000} \times 100 = 1.5 %

Therefore, strength of H₂O₂ in 5 volume H₂O₂ solution

= 15 g / L = 1.5 % H_{2} O_{2}

solution.