4.What is the mole fraction of solute in a 3.66 m aqueous solution?
5.You need to dissolve CaCl2 in water to make a mixture that is 38.0% calcium chloride by mass. If the total mass of the mixture is 832.9 g, what masses of CaCl2 and water should be used?
6. What is the mole fraction, X, of solute and the molality, m (or b), for an aqueous solution that is 14.0% NaOH by mass?
15. Biphenyl, C12H10, is a nonvolatile, nonionizing solute that is soluble in benzene, C6H6. At 25 °C, the vapor pressure of pure benzene is 100.84 torr. What is the vapor pressure of a solution made from dissolving 10.5 g of biphenyl in 30.4 g of benzene?
16. A solution is made by mixing 30.0 mL of ethanol, C2H6O, and 70.0 mL of water. Assuming ideal behavior, what is the vapor pressure of the solution at 20 °C?
Values at 20 degrees Celcius
ethanol : density (g/mL)= 0.789/ vapor pressure (torr)= 43.9
water: density (g/mL) =0.998/ vapor pressure (torr)= 17.5
18. A solution is made by dissolving 0.554 mol of nonelectrolyte solute in 813 g of benzene. Calculate the freezing point, Tf, and boiling point, Tb, of the solution.
20.Vitamin K is involved in normal blood clotting. When 1.72 g of vitamin K is dissolved in 25.0 g of camphor, the freezing point of the solution is lowered by 5.77 °C. The freezing point and Kf constant for camphor needs to be found for this question. Calculate the molar mass of vitamin K.
21.The boiling point of an aqueous solution is 101.34 °C. What is the freezing point? Constants can be found here.
22.When 4.41 g of a nonelectrolyte solute is dissolved in water to make 405 mL of solution at 25 °C, the solution exerts an osmotic pressure of 889 torr.
What is the molar concentration of the solution?
How many moles of solute are in the solution?
What is the molar mass of the solute?
24. Assuming 100% dissociation, calculate the freezing point and boiling point of 3.46 m SnCl4(aq). Constants are needed.
26. If an 0.740 m aqueous solution freezes at -3.70 °C, what is the van't Hoff factor, i, of the solute? Kf values are needed.