0.023g of sodium metal is reacted with `100 cm^(3)` of water. The pH of the resulting solution is :

Options

A. 10
B. 8
C. 9
D. 12

Answer

D

Explanation

Molarity of solution ,`M=(wt.)/(m.wt)xx(1)/(V(L))`
`=(0.023)/(23)xx(1000)/(100)=(0.23)/(23)=10^(-2)`M
`2Na+2OH^(-)2H^(+)to2NaOH+H_(2)`
In this reaction sodium reacts with `OH^(-)` ions and form NaOH solution.
Here,`[OH^(-)]`=0.01M,pOH=-log(0.01)
pOH=-(-2)=2
`therefore` pH=14-pOH=14-2=12