Question

1litre solution of NaOH contains 4g of it. What shall be the difference between molarity and the normality?

• A. 0.1
• B. 0
• C. 0.05
• D. 0.2

Answer 1

Answer: (B)

0

As we know that,

$\text{no. of moles}=\frac{\text{Wt.}}{\text{Mol. wt.}}$

Mol. wt. of $NaOH=40g$

Wt. of $NaOH=4g\left(\text{Given}\right)$

Therefore,

No. of moles $=\frac{4}{40}=0.1\text{mol}$

As we know that molarity of a solution is defined as the no. of moles of solute present in $1L$ of solution.

Since $0.1$ mole of $NaOH$ are present in $1L$ of solution.

Therefore,

Molarity of solution $\left(M\right)=0.1$

As we also know that,

Normality $=$ molarity $\times$ equivalents

$\because$ No. of equivalents per mole of $NaOH=1$

Therefore,

$N=0.1\times 1=0.1$

$\because N=M=0.1$

Hence the difference between normality and molarity is $0$.