Question

What is the $pH$ of the $NaOH$ solution when $0.04gm$ of it dissolved in water and made to $100ml$ solution?

• A. $2$
• B. $1$
• C. $13$
• D. $12$

Answer 1

The correct option is D $12$

First of all, you have to calculate the concentration:

$\left[NaOH\right]=\frac{\left(0.04/40\right)}{0.1}=0.01M$

Now, sodium hydroxide is monoacidic, so

$\left[NaOH\right]=\left[O{H}^{-}\right]=0.01M$

$⟹pOH=-log\left(0.01\right)=2$

$⟹pH=14-pOH=14-2=12$

$pH=12$