Question

Calculate `pH` of a solution whose `100ml` contains `0.2g NaOH` dissolved in it.
A. `10.699`
B. `11.699`
C. `12.699`
D. `13.699`

Answer 1

Correct Answer - C
`100ml` solution of `NaOH` contains
` =0.2 g NaOH`
`:. 1000ml` solution of `NaOH` contains ` =2 g NaOH`
Normality of solution `= (2)/(40)=0.05 N`
`:. [H^(+)]=(10^(-14))/(0.05)`
`:. -loh[H^(+)]= -log[(10^(-14))/(0.05)]`
` = -[-14+2-0.6990]=12.699`