Question

250 ml of a sodium carbonate solution contains 2.65 grams of $N{a}_{2}C{O}_3$. If 100 ml of this solution is diluted to one litre, what is the concentration of the resultant solution?

• A. $0.1M$
• B. $0.01M$
• C. $0.001M$
• D. ${10}^{-4}M$

Answer 1

Answer: (B)

$0.01M$

Moles of $N{a}_{2}C{O}_3$ is $\frac{2.65}{105.9}=0.0250$

Molarity is $M_1=0.025\times \frac{1000}{250}$

Now, $M_1\times V_1=M_2{V}_2$

$\frac{25}{250}\times 100=M_2\times 1000$

$M_2=0.01M$

So, the correct option is $B$