Calculate the boiling tempature for a solution which contains 0.325 mol of calcium phosphate (Ca3(PO4)2) dissolved into 240.0 g of water.
To calculate the boiling temperature elevation for a solution, we can use the equation:
ΔTb = Kb * m * i
where:
- ΔTb is the boiling temperature elevation
- Kb is the molal boiling point elevation constant (which is specific for each solvent)
- m is the molality of the solute (moles of solute per kilogram of solvent)
- i is the van't Hoff factor
First, let's calculate the molality (m) of the solution:
m = moles of solute / mass of solvent (in kg)
Given:
moles of calcium phosphate (Ca3(PO4)2) = 0.325 mol
mass of water = 240.0 g = 0.240 kg
m = 0.325 mol / 0.240 kg
m ≈ 1.35 mol/kg
Next, we need to determine the van't Hoff factor (i) for calcium phosphate. The van't Hoff factor represents the number of particles per formula unit in the solution. Since calcium phosphate dissociates into three calcium ions and two phosphate ions, i = 5.
Finally, we need to look up the molal boiling point elevation constant (Kb) for water. The value for water is 0.512 °C/m.
Now we can calculate the boiling temperature elevation (ΔTb):
ΔTb = Kb * m * i
ΔTb = 0.512 °C/m * 1.35 mol/kg * 5
ΔTb ≈ 3.44 °C
Therefore, the boiling temperature of the solution will increase by approximately 3.44 °C. To find the actual boiling temperature, you would add this value to the normal boiling temperature of water, which is 100 °C at sea level.