Respuesta :
Answer: The freezing point of solution is 5.35°C
Explanation:
The equation used to calculate depression in freezing point follows:
[tex]\Delta T_f=\text{Freezing point of pure solution}-\text{Freezing point of solution}[/tex]
To calculate the depression in freezing point, we use the equation:
[tex]\Delta T_f=iK_fm[/tex]
Or,
[tex]\text{Freezing point of pure solution}-\text{Freezing point of solution}=i\times K_f\times \frac{m_{solute}\times 1000}{M_{solute}\times W_{solvent}\text{ (in grams)}}[/tex]
where,
Freezing point of pure solution = 5.5°C
i = Vant hoff factor = 1 (For non-electrolytes)
[tex]K_f[/tex] = molal freezing point elevation constant = 4.90°C/m
[tex]m_{solute}[/tex] = Given mass of solute (naphthalene) = 2.60 g
[tex]M_{solute}[/tex] = Molar mass of solute (naphthalene) = 128.2 g/mol
[tex]W_{solvent}[/tex] = Mass of solvent (benzene) = 675 g
Putting values in above equation, we get:
[tex]5.5-\text{Freezing point of solution}=1\times 4.90^oC/m\times \frac{2.60\times 1000}{128.2g/mol\times 675}\\\\\text{Freezing point of solution}=5.35^oC[/tex]
Hence, the freezing point of solution is 5.35°C
