Question

How much water should be added to 200 cc of semimolar solution of NaOH to make it exactly decimolar:-
(A) 1000 cc (B) 400 cc (C) 800 cc (D) 600 cc

Answer 1

The correct answer is C

200 cc= 100 ml

semi normal=$\frac{N}{2}$

so $\frac{equivalentofNaoH}{0.2}$=$\frac{1}{2}$

So, equivalent of NaoH= 0.1

let volume of water is X L

then $\frac{0.1}{(0.2+X)}$=$\frac{1}{10}$

$1=0.2+x$

so, x= 0.8l=800 ml=800cc