Question

A solution prepared by dissolving 2.8 g of lime (CaO) in enough water to make 1.00 L of lime water (Ca(OH)2(aq.)). If solubility of Ca(OH)2 in water is 1.48 gm/lt. The pH of the solution obtained will be:

[log 2 = 0.3, Ca = 40 , O = 16, H = 1]

• A. 12.3
• B. 12.6
• C. 1.3
• D. 13

Answer 1

Answer: (B)

12.6

Answer 2

Ca(OH)2 $\rightleftharpoons$ Ca2+ + 2OH–

t = 0 $\frac{1.48}{74}$ = 0.02 0 0

teq 0 0.02 0.04

so, pOH = 2 – log 4 = 1.4

so pH = 12.6