What is the predicted change in the boiling point of water when 4.00 g of barium chloride (BaCl2) is dissolved in 2.00 kg of water?
Kb of water = 0.51°C/mol
molar mass BaCl2 = 208.23 g/mol
i value of BaCl2 = 3
To find the predicted change in the boiling point of water, we can use the formula:
ΔTb = i * Kb * m
where ΔTb is the change in boiling point, i is the van't Hoff factor, Kb is the molal boiling point elevation constant of the solvent, and m is the molality of the solute.
Given:
- Kb of water = 0.51 °C/mol
- molar mass BaCl2 = 208.23 g/mol
- i value of BaCl2 = 3
- mass of BaCl2 = 4.00 g
- mass of water = 2.00 kg
First, we need to calculate the molality of the solute:
Molality (m) = moles of solute / mass of solvent (in kg)
The moles of BaCl2 can be calculated using its molar mass:
moles of BaCl2 = mass of BaCl2 / molar mass of BaCl2
Next, we convert the mass of water from kg to g:
mass of water = 2.00 kg * 1000 g/kg = 2000 g
Now we can calculate the molality:
m = moles of BaCl2 / mass of water (in kg)
Finally, we can find the change in boiling point using the formula:
ΔTb = i * Kb * m
Let's calculate it step by step:
1. Calculate the moles of BaCl2:
moles of BaCl2 = 4.00 g / 208.23 g/mol
2. Convert the mass of water to kg:
mass of water = 2000 g / 1000 = 2.00 kg
3. Calculate the molality:
m = moles of BaCl2 / mass of water (in kg)
4. Plug in the values into the formula to find the change in boiling point:
ΔTb = 3 * 0.51 °C/mol * m
By following these steps and substituting the values given, you can find the predicted change in the boiling point of water.