Vapor Pressure, Freezing Point and Boiling Point Review
Name: ______Date: ______
Answer the questions below using the provided data table and your reference table.
Solvent / Formula / P0A (kPa) / Tf (°C) / Kf (°C/m) / Tb (°C) / Kb (°C/m)Acetic acid / C2H4O2 / 1.5 / 16.6 / 3.63 / 117.9 / 3.22
Acetone / C3H6O / 24.0 / -94.81 / 2.40 / 56 / 1.80
Benzene / C6H6 / 12.69 / 5.5 / 5.07 / 80.15 / 2.53
Carbon tetrachloride / CCl4 / 12.2 / -23 / 29.8 / 76.5 / 5.03
Glycerol / C3H8O3 / 10.0 / 18.2 / 3.56 / 290 / 6.52
Toluene / C7H8 / 3.8 / -94.91 / 3.55 / 110.6 / 3.33
1. If the boiling point of 86 g of glycerol is raised by 19.6°C, how many grams of calcium chloride must be dissolved in it?
2. What is the molar mass of an unknown covalent solute if 57.9 g of it added to 97.0 g of toluene causes the solution to freeze at -120°C?
3. How many grams of sodium hydroxide must be dissolved in 100 g of acetone in order to lower the vapor pressure of the solution by 6.0 kPa?
4. At STP what temperature will an aqueous solution containing 164 g of iron (II) sulfate freeze at?
5. What is the mole fraction of benzene in a solution of glucose dissolved in benzene that has a vapor pressure of 15.76 kPa?
6. What is the boiling point elevation when 97.3 g of carbon disulfide is dissolved in 276 g of benzene?
7. How many kilograms of acetic acid must be present if a solution containing 291 g of sodium chloride dissolved in acetic acid has a freezing point of 11°C?
8. How many moles of magnesium bromide must be dissolved in 173 g of water in order for the solution to boil at 103°C at STP?
9. A solution of 152 g of methanol (CH3OH) in 187.2 g of an unknown solvent has a vapor pressure of 21.3 kPa. What is the vapor pressure of the pure solvent?
10. What is the freezing point depression of a solution containing 19.7 g of sucrose (C12H22O11) in 200 g of carbon tetrachloride?