What are the boiling point of a solution prepared by dissolving 2.40g of biphenyl(C^12H^10) in 75.0g of benzene? The molecular weight of biphenyl is 154..
To find the boiling point of a solution, you would need to apply the concept of boiling point elevation. The boiling point of a solution is higher than that of the pure solvent due to the presence of a solute.
To calculate the boiling point elevation, you can use the equation:
ΔT = K_b * m
where:
ΔT is the boiling point elevation
K_b is the molal boiling point elevation constant of the solvent
m is the molality of the solution
First, calculate the molality (m) of the solution using the formula:
molality (m) = moles of solute / mass of solvent (in kg)
1. Convert the mass of biphenyl into moles by dividing it by the molar mass:
moles of biphenyl = mass of biphenyl / molar mass of biphenyl
= 2.40 g / 154 g/mol
2. Convert the mass of benzene into kilograms:
mass of benzene (kg) = mass of benzene / 1000
3. Calculate the molality:
molality = moles of solute / mass of solvent (in kg)
= moles of biphenyl / mass of benzene (kg)
Now, you need to find the molal boiling point elevation constant (K_b) of benzene. In this case, the value is 2.53 °C/m.
Finally, plug in the values into the boiling point elevation equation:
ΔT = K_b * m
By solving this equation, you will find the boiling point elevation (ΔT) of the solution. To find the boiling point of the solution, you would add the boiling point elevation to the boiling point of the pure solvent (benzene). The boiling point of pure benzene is 80.1 °C.