15.Assuming that sea water is a 3.5 wt % solution of NaCl in water, calculate its osmotic pressure at 20°C. The density of a 3.5% NaCl solution at 20°C is 1.023 g/mL.
(A) 1.0 atm
(B) 15 atm
(C) 29 atm
(D) 100 atm

11.Which should be least soluble in water? (A) (B) (C) (D)

12.A solution is prepared by dissolving 17.75 g sulfuric acid, H2SO4, in enough water to make 100.0 mL of solution. If the density of the solution is 1.1094 g/mL, what is the molality? (A) 0.1775m H2SO4 (B) 0.1810 m H2SO4 (C) 1.810 m H2SO4 (D) 1.940 m H2SO4

13.n general, as the temperature increases, the solubility of gases in water ______ and the solubility of most solids in water ______. (A) decreases, decreases (B) decreases, increases (C) increases, decreases (D) increases, increases

14.A solution is prepared by dissolving 20.0 g of sucrose, in 250. g of water at 25°C. What is the vapor pressure of the solution if the vapor pressure of water at 25°C is 23.76 mm Hg? (A) 0.198 mm Hg (B) 20.5 mm Hg (C) 23.7 mm Hg (D) 24.0 mm Hg

16.A solution of a nonelectrolyte solution contains 30.0 g of solute dissolved in 250.0g of water. The freezing point of the water is observed to be -2.50°C. The Kf for water is 1.86 °C/m and normal freezing point of water is 0.00'C. What is the molar mass of the substance? (A) 335 g/mol (B) 89.5 g/mol (C) 895 g/mol (D) 33.5 g/mol

17.Which arrow represents ? (A) arrow (a) (B) arrow (b) (C) arrow (c) (D) arrow (d)

18.Which arrow represents ? (A) arrow (a) (B) arrow (b) (C) arrow (c) (D) arrow (d)

19. The following diagram shows a close-up view of the vapor pressure curves for a pure solvent and a solution containing a nonvolatile solute dissolved in this solvent. Which curve is the solvent and what happens to the vapor pressure when the solute is dissolved in the solvent? (A) Curve (a) is the solvent and the vapor pressure decreases. (B) Curve (a) is the solvent and the vapor pressure increases. (C) Curve (b) is the solvent and the vapor pressure decreases. (D) Curve (b) is the solvent and the vapor pressure increases.

20. What is the mole fraction of oxygen in a gas mixture that is 27% oxygen and 73% nitrogen by volume? (A) 0.24 (B)0.27 (C) 0.32 (D)0.37

21.A concentration-time study of the gas phase reaction 2 A3 - 3 A2 produced the data in the table below. What is the concentration of A2 after 30 seconds? (A) 5.00 x 10*M (B) 5.25 x 10*M (C) 5.50 x 10*M (D) 6.00 x 10*M