Question

Calculate the freezing temperature of an aqueous solution having its boiling temperature ${100.1}^{o}C$. The molal ebullioscopic constant and the molal cryoscopic constant are 0.513 deg and 1.86 deg, respectively. The answer is -0.mn then m+n =____.

Answer 1

$\Delta T_b=0.1;K_b=0.513$

$0.1=0.513m,\Rightarrow m=\frac{0.1}{0.513}$

$\Delta T_f=K_{f}m=1.86\times \frac{0.1}{0.513}=0.3625$

$\Delta T_f=T_o-T_S$

$0.3625=0-T_S$

$\therefore$ Freezing point =$-{0.36}^{o}C$

But freezing point is $-0.mn$

Thus m=3 and n= 6

Hence, m+n=9