Question

4 L of $0.02$M aqueous solution of NaCl wad diluted by adding one litre of water. The molality of the resultant solution is ________.

• A. $0.004$
• B. $0.008$
• C. $0.012$
• D. $0.016$

Answer 1

Answer: (D)

$0.016$

Answer 2

$0.02 \mathrm { M } \times 4 \mathrm {~L} = \mathrm { M } _ { 2 } \times 5 \mathrm {~L}$

$\mathrm { M } _ { 2 } = \frac { 0.02 \times 4 } { 5 } = 0.016 \mathrm { M }$

Here, molality will be equal to molarity as for NaCl, molecular weights is equal to its equivalent weight.