Which of the following solution will have pH = 13 on assuming complete dissociation

Options

A. 100 ml of solution of 0.1 N` Mg (OH)_2`
B. 0. 56 g of KOH in 100 ml solution
C. 4 g of NaOH in 500 ml solution
D. 100 ml of solution of 0.05 M Mg ` (OH)_2`

Answer

A, B, D

Explanation

(a) ` [OH^(-) ] =0.1 N , pOH = 1 rArrpH =13`
(b) ` n= ( 0. 56)/( 56) rArr M= ( 0.01)/( 0.1 ) =0.1`
`rArr POH =1 rArr pH = 13`
( c ) ` n= 4 //40 =0.1 rArr M =(0.1)/( 0.5) =0.2`
`rArr p = 14 - 1 log 2 =13.3`
(d) ` [OH^(-)] =2 xx 0.05 = 0.1 `
`pOH =1 rArr pH =13`
` NH_3 +H_2O hArr NH_4OH hArr NH_4^(+) +OH^(-) `
` C_1(1-alpha _1) C_1alpha _1 =C_2 `
`" " C_2( 1-alpha_2)C_2alpha _2 = C_3`