p. 82 # 1-8

ISCS P. 82

1) Three teaspoons of sugar will completely dissolve in a serving of hot tea, but will not dissolve in an equally sized serving of iced tea because sugar is less soluble in cold water.

2) The maximum mass of potassium chloride that will dissolve in 100.0 g water at 70 degrees C is 50 g of potassium chloride. 

3) If the solubility of sugar (sucrose) in water is 2.0 g/mL at room temperature, the maximum mass of sugar that will dissolve is

a) 200 g
b) 710 g

c) 1,892 g

4) a) At 20 degrees C, NaCl is most soluble, second comes KCl, then KNO3 

    b) 80 degrees C, KNO3 is most soluble, then KCl and, lastly, NaCl 

5) A saturated solution is the maximum amount of solute that dissolves in a solvent at a specific temperature, as opposed to unsaturated, which is a solution that contains less dissolved solute than the amount that the solvent can normally hold at that temperature. 

6) Using the graph on p. 54, answer these questions about the solubility of potassium nitrate, KNO3 

a) 30 g
b) supersaturated 

c) 90 g

7) a)You are given a solution of KNO3 of unknown concentration. A crystal  will just dissolve if you add crystal of KNO3 in an unsaturated solution.
    b) If we added a crystal to the saturated solution, the solution would become supersaturated.
    c) If we added a crystal to a supersaturated solution the solution would stay supersaturated 

8) A 35-g sample of ethanol is dissolved in 115 g water. 30% is the percent concentration of the ethanol, expressed as percent ethanol by mass.