Question

In the aqueous solution of sulphuric acid, the mole fraction of water is $0.849$. The molality of the solution is:

• A. $8.9m$
• B. $0.19m$
• C. $9.8m$
• D. $15m$

Answer 1

Answer: (C)

$9.8m$

$A\to solute$

$B\to solvent$

$\frac{X_A}{(1-X_A)m_B}\times 1000=m$

where, $m_B$ is the molecular weight of solvent and $X_A$ is the mole fraction of solute.

$m=\frac{1-0\cdot 849}{0\cdot 849\times 18}\times 1000$

$m=9\cdot 88m$