1. Ch 12 – Solutions Ch 13 – Colligative Properties Review Your group may use/have out: calculator, another book turned to 448, PC, ion chart, 2 white boards, 1 marker, 1 eraser.

2. 1.As temperature increases, the solubility of gases in liquids generally: decreases 2.With regard to temperature increasing, collisions become ___ frequent and ___ energetic. more and more 3. What are 2 of 3 ways to increase the rate at which a solid dissolves in a solvent? stirring, raising temp., and make solid size smaller

3. 4. MgSO 4. 6H 2 0 goes by what name or category/name? magnesium sulfate hexahydrate or hydrate 5. A mixture that is homogeneous and in which the dispersed solute do not settle out is ___. solution 6. A solution must contain ___ in order to conduct electric current. ions 7.Molecules that can conduct electric current when in solution must ___. ionize

4. 8. A mixture that can scatter light is a(n) ___. colloid 9. An ion that does NOT take part in a chemical reaction is a(n) ___. spectator ion 10. Is sodium carbonate soluble in aqueous solution? yes 11. Is calcium carbonate soluble in aq. Solution? no 12. Is strontium sulfate soluble in aq. Solution? no

5. 13. Write the formula for sodium carbonate. Na 2 CO 3 14. Write the formula for strontium nitrate. Sr(NO 3 ) 2 15. Write the balanced formula equation that shows the possible products of a double-displacement reaction between sodium carbonate and strontium nitrate. Na 2 CO 3 (aq) + Sr(NO 3 ) 2 (aq) --> 2NaNO 3 (aq) + SrCO 3 (S) Don’t erase the formula equation.

6. 16. What is the net ionic equation for the prior equation? Na 2 CO 3 (aq) + Sr(NO 3 ) 2 (aq) --> 2NaNO 3 (aq) + SrCO 3 (S) 2Na +1 + CO 3 -2 + Sr +2 + 2NO 3 -1 --> 2Na +1 + 2NO 3 -1 + SrCO 3 (S) CO 3 -2 (aq) + Sr +2 (aq) --> SrCO 3 (S) 17. What are the spectator ions in the balanced formula equation? 2Na +1 + 2NO 3 -1 18.When energy released by formation of solvent-solute attraction is greater than energy absorbed by overcoming solute-solute and solvent-solvent attractions, the dissolving process ___. has a negative enthalpy of solution or is exothermic

7. 19. A solution of 5.00 g of a nonelectrolyte solution in 40.0 g of water (Kb = 0.52 o C/m has a boiling point elevated by 2.00 o C. What is the molar mass of the solute? m =  t b = 2.00 o C m = 3.8461 = 3.85 m K b 0.52 o C m = mole solute  kg solvent mole = 3.85 mole x 0.040 kg solv = 0.154 mole kg solv Molar mass = 5.00g / 0.154 mol = 32.467 = 32.5 g/mol 20. The boiling point of a solvent is elevated by 6.5 o C when the solute concentration is 4.0 m. What is the Kb? Kb =  t b = 6.5 o C = 1.625 = 1.6 o C m 4.0 m m

8. 21. 40.0 g of a substance can be dissolved in 250. g of water. What is the solubility of the substance in grams per 100. g of water? 40.0 = x--> x = 40(100) = 16 g 250 100 250 22. What is the expected change in the freezing point of water for a 0.725 m aqueous solution of Mn(NO 3 ) 2 ? Kf = -1.86 o C/m.  tf = m Kf = 0.725m (-1.86 o C) = -1.3485 = -1.35 o C m

9. 23. What mass of water (in g) must be used to make a 2.60 m solution that contains 5.20 mol of HCl? molality, m = mole solute kg solvent Kg solvent = mole solute = m Mass water = 5.20 mole solute kg water 2.60 mole solute Mass = 2 kg = 2000g = 2.00 x 10 3 g water