A solution containing `0.5216g` of naphthalene (mol.wt.`=128.16`) in 50mL of `"CC"l_(4)` shows boiling point elevation of `0.402^(@)` while a solution of `0.6216g` of an unknown solute in the same weight of solvent gave a boiling point elevation of `0.647^(@)` . Find the molecular mass of the unknown solute.

Explanation

To solve the problem step by step, we will use the formula for boiling point elevation and the concept of molality.

### Step 1: Calculate the number of moles of naphthalene
We start by calculating the number of moles of naphthalene using its mass and molar mass.

\[ \text{Number of moles of naphthalene} = \frac{\text{mass}}{\text{molar mass}} = \frac{0.5216 \, \text{g}}{128.16 \, \text{g/mol}} \]
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