Question

What will be the normality of a solution obtained by mixing $0.5NCa(OH{)}_2$ and $0.5NMg(OH{)}_2$ solution in the ratio $1:5$ by volume?

• A. $0.20N$
• B. $0.15N$
• C. $0.5N$
• D. $0.25N$

Answer 1

The correct option is C $0.5N$

Let volume of $0.5NCa(OH{)}_2=V$
Volume of $0.5NMg(OH{)}_2=5V$
Now,

$N_1{V}_1+N_2{V}_2=N_3{V}_3$​

where, $N_1,N_2$​ are the normality of $Ca(OH{)}_2$ and $Mg(OH{)}_2$ respectively and $V_1$​ and $V_2$​ are their volumes respectively.

$N_3$​ and $V_3$​ are the normality & volume of the final solution.

$(0.5\times V)+(0.5\times 5V)=N_3\times (V+5V)0.5V+2.5V=N_3\times 6V{N}_3=0.5N$
The normality of the solution is $0.5N.$