Analytical Chemistry Question 276
Question: Weight of $ Ca{{(OH)}_2} $ needed to prepare 250 ml of solution with pH = 13
[BVP 2004]
Options:
A) 0.925 g
B) 0.0125 g
C) 0.25 g
D) 1 g
Show Answer
Answer:
Correct Answer: A
Solution:
We know, $ [{H^{+}}]\ ={10^{-pH}}={10^{-13}}; $
$ \therefore \ [O{H^{-}}]=\frac{{10^{-14}}}{{10^{-13}}}={10^{-1}} $ Hence, normality of solution = 0.1 We know, w = $ \frac{NEV}{1000}=\frac{0.1\times 74\times 250}{2\times 1000}=0.925\ gm $
BETA
