Question

The strengths of $5.6$ volume hydrogen peroxide (of density $1g/mL)$ in terms of mass percentage and molarity (M), respectively, are:
(Take molar mass of hydrogen peroxide as $34g/mol)$

• A. $1.7$ and $0.25$
• B. $1.7$ and $0.5$
• C. $0.85$ and $0.5$
• D. $0.85$ and $0.25$

Answer 1

Answer: (B)

Volume strength $=11.2\times$ molarity

$\Rightarrow$ molarity $=\frac{5.6}{11.2}=0.5$

Assuming 1 litre solution;

mass of solution $=1000ml\times 1g/ml=1000g$

mass of solute = moles $\times$ molar mass

$=0.5mol\times 34g/mol$

$=17gm$

$\Rightarrow$ mass $\%=\frac{17}{1000}\times 100=1.7\%$