Question

Mole fraction of the solute in a 1.00 molal aqueous solution is
(a) 0.1770 (b) 0.0177 (c) 0.0344 (d) 1.7700

Answer 1

Therefore mole fraction = 17.6 × 10³

Explanation:

$\textrm{mole fraction of solute}=\frac{\textrm{No.mole of solute}}{\textrm{No.mole of solute}+\textrm{No.mole of solvent}}$

Given, mole fraction of solute in a 1.00 molar aqueous solution it means 1 mole of solute is mixed with 1 kg= 1000 gram of solvent (water).

Atomic mass of H₂O is = (2×1) +16 = 18

No. of mole in 1000 gram of water = $\frac{1000}{18}$

$\textrm{mole fraction of solute}=\frac{1}{\frac{1000}{18}+1 }$

                                   $=\frac{18}{1018}$

                                   $=17.6 \times 10^3$

Therefore mole fraction = 17.6 × 10³