Determine the boiling point of a solution contanting 36.1grams calcium chloride molar mass 112 in 200.0grams water.
mols CaCl2 = grams/molar mass
Substitute and solve for mols.
molality = mols/kg solvent
Substitute and solve for m.
Then delta T = i*Kb*m
i = 3 for CaCl2.
Forgot. The problem asks for the boiling point. The above calculate delta T. Add delta T to normal boiling point for new boiling point.
To determine the boiling point of the solution, you need to use the concept of boiling point elevation, which states that the boiling point of a solution is higher than that of the pure solvent. The boiling point elevation is directly proportional to the molality of the solute – the number of moles of the solute per kilogram of the solvent.
To calculate the boiling point elevation, you can use the following formula:
ΔTb = Kb * m
Where:
ΔTb is the boiling point elevation,
Kb is the molal boiling point elevation constant for the solvent (water), and
m is the molality of the solution (moles of solute per kilogram of solvent).
First, let's calculate the molality of the solution:
Step 1: Calculate the number of moles of calcium chloride (CaCl2):
Moles of CaCl2 = Mass of CaCl2 / Molar mass of CaCl2
Moles of CaCl2 = 36.1 g / 112 g/mol
Step 2: Convert the mass of water to kilograms:
Mass of water = 200.0 g = 200.0 g / 1000 g/kg
Step 3: Calculate the molality (moles of solute per kilogram of solvent):
Molality (m) = Moles of CaCl2 / Mass of water
Now that you have calculated the molality, you can calculate the boiling point elevation:
Step 4: Look up the molal boiling point elevation constant (Kb) for water. For water, Kb = 0.512 °C/m.
Step 5: Calculate the boiling point elevation (ΔTb):
ΔTb = Kb * m
Finally, add the boiling point elevation to the boiling point of pure water (which is 100°C) to get the boiling point of the solution.
Note: This calculation assumes ideal behavior and excludes factors such as intermolecular interactions or dissociation of solute particles.