when 5.00 g of CaCl2 dissolves in 50.0g of water, what is the boiling point of the solution
moles CaCl2 = grams/molar mass.
Solve for moles.
molality = moles/kg solvent
Solve for molality.
delta T = Kb*m
Solve for delta T.
Then add to 100 to find the boiling point in degrees C.
To find the boiling point of the solution, we need to use 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 solute particles.
To calculate the boiling point elevation, we can use the following formula:
ΔTb = K_b * m
Where:
- ΔTb = boiling point elevation
- K_b = molal boiling point constant (a specific property of a solvent, in this case, water)
- m = molality of the solution (moles of solute per kilogram of solvent)
To solve the problem, we need to follow these steps:
Step 1: Convert the mass of CaCl2 to moles.
- Molar mass of CaCl2 = 40.08 g/mol (Ca: 40.08 g/mol, Cl2: 2 * 35.45 g/mol)
- Moles of CaCl2 = mass / molar mass = 5.00 g / 40.08 g/mol
Step 2: Calculate the molality (m) of the solution.
- Molality (m) = moles of solute / mass of solvent (in kg)
- Mass of water = 50.0 g
- Convert mass of water to kg: mass_water = 50.0 g / 1000 g/kg
- Molality (m) = moles of CaCl2 / mass_water
Step 3: Find the molal boiling point constant (K_b) for water.
- The molal boiling point constant for water is approximately 0.512 °C/m.
Step 4: Calculate the boiling point elevation (ΔTb).
- ΔTb = K_b * m
Step 5: Add the boiling point elevation (ΔTb) to the boiling point of pure water.
- The boiling point of pure water at normal atmospheric pressure is 100 °C.
ΔTb = 0.512 °C/m * (moles of CaCl2 / mass_water)
Boiling point of solution = 100 °C + ΔTb
By following these steps, you can calculate the boiling point of the solution.