Chemistry - Concentration Terms Question with Solution | TestHub

Let $m_1$ and $m_2$ be the masses of solvent in solutions I and II, respectively.

The total moles of solute are $1.5m_1+3m_2$.

The total mass of solvent is $m_1+m_2$.

The final molality is 2 m:

$$\frac{1.5m_1+3m_2}{m_1+m_2}=2$$

$$1.5m_1+3m_2=2m_1+2m_2$$

$$m_2=0.5m_1⟹\frac{m_1}{m_2}=\frac{2}{1}$$

So, statement (II) is correct.

Mass of solution I = $m_1+1.5\times 60\times m_1/1000=m_1(1+0.09)=1.09m_1$

Mass of solution II = $m_2+3\times 60\times m_2/1000=m_2(1+0.18)=1.18m_2$

Ratio of masses of solutions = $\frac{1.09m_1}{1.18m_2}=\frac{1.09}{1.18}\times \frac{2}{1}=\frac{2.18}{1.18}=\frac{109}{59}$

So, statement (III) is correct.