Question

Assertion :Concentration of $H_2{O}_2$ is expressed in volume. Reason: Volume strength of $H_2{O}_2=Normality\times 5.6$.

• A. Both Assertion and Reason are correct and Reason is the correct explanation for Assertion
• B. Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion
• C. Assertion is correct but Reason is incorrect
• D. Assertion is incorrect but Reason is correct

Answer 1

The correct option is B Both Assertion and Reason are correct but Reason is not the correct explanation for Assertion

In this question both Assertion and Reason

are correct however Reason is not the

correct explanation for Assertion as from

the solution it is clear that strength of

$H_2{O}_2$ is just a term to express conc. of $H_{2}O2$

in terms of volumes of oxygen gas based

on its decomposition to from water and

oxygen. This has nothing to do with normality

$2H_2+O_2\rightleftharpoons 2H_{2}O+O_2$

Lets say we have M moles $H_2{O}_2$ in

$1L$ solution.

$\therefore$ from the given reaction

2 moles $H_2{O}_2$ gives 1 mol of $O_2$ i.e $22.4m$

$\therefore$ 1 mole of $H_2{O}_2$ gives $(11.2\times M)L$ of $O_2$

$1L$ of $H_2{O}_2$ gives $(11.2\times M)L$ of $O_2$

$\therefore$ Volume of $H_2{O}_2=11.2\times M$

n factor of $H_2{O}_2$ is $2$

Now,

Normality $=$ Morality $\times$ n factor

$N=M\times 2$

$\Rightarrow M=\frac{N}{2}...\left(1\right)$

Volume $\Rightarrow M\times 11.2$

Strength $\Rightarrow 11.2\times \frac{N}{2}....\left(2\right)$