Determine the boiling point(bp)of 0.44 m Naphthalene, C10H8, in Benzene, C6H6. kb(C6H6)=2.53, bp(C6H6)=80.1
delta T = Kb*m
Solve for delta T and add to the normal boiling point of benzene to find the new boiling point.
To determine the boiling point of a solution, you can use the following formula:
ΔT = kb * m
Where:
- ΔT represents the change in boiling point
- kb is the molal boiling point elevation constant for the solvent
- m is the molality of the solute (in this case, naphthalene)
First, we need to calculate the molality (m) of the naphthalene solution.
Molality (m) is defined as the number of moles of solute per kilogram of solvent.
Given:
- Mass of naphthalene (C10H8) = 0.44 m
- Molar mass of naphthalene (C10H8) = 128.176 g/mol
- Mass of benzene (C6H6) = 1 kg
- Molar mass of benzene (C6H6) = 78.114 g/mol
Step 1: Calculate the number of moles of naphthalene:
moles of naphthalene (C10H8) = (mass of naphthalene / molar mass of naphthalene)
= (0.44 m / 128.176 g/mol)
Step 2: Calculate the mass of benzene (C6H6) in kg:
mass of benzene (C6H6) = (mass of benzene in g) / 1000
= 1 kg
Step 3: Calculate the molality (m) of the solution:
molality (m) = (moles of solute / mass of solvent in kg)
= (moles of naphthalene / mass of benzene)
Now, we can calculate the boiling point elevation (ΔT) using the formula provided and the known value of kb (molal boiling point elevation constant for benzene).
Step 4: Calculate ΔT:
ΔT = kb * m
Given:
- kb (C6H6) = 2.53 °C/molal
Now, we can substitute the calculated value of molality (m):
ΔT = (2.53 °C/molal) * molality
Finally, we can calculate the boiling point (bp) of the naphthalene solution by adding ΔT to the boiling point of benzene (C6H6).
Step 5: Calculate the boiling point of the solution:
bp = bp(Benzene) + ΔT
Given:
- bp(Benzene) = 80.1 °C
Now, substitute the known values:
bp = 80.1 °C + ΔT
By following these steps, you can calculate the boiling point of the 0.44 m naphthalene solution in benzene.