1. At which temperature do NaNO3 and KNO3 have the same solubility?

2. 100 g of water saturated with KCIO, is cooled from 50°C to 30°C. How much solid crystallizes?

3. How much NH4Cl is needed to saturate 50 g of water at 35°C2

4. Which substance on the graph shows the smallest increase in solubility over the range 80°C to 100°C?

5. Which of the substances on the graph have approximately the same solubility over the range 20°C to 25°C?

6. 321 g of KNO3 are used to saturate water at 60°C. What is the mass of water that is used?

7. When a saturated solution of KCIO, at 24°C is evaporated to dryness, the mass decreases 200 g. How much solid remains?

8. What is the smallest mass of water necessary to dissolve 40 g of NH3 completely at 4°C?

9. Which of the substances on the graph has a solubility that is relatively unaffected by changes in temperature?

10. Which substances on the graph have solubilities that decrease with increases in temperature?

11. 30 g of Kl are dissolved in 300 g of water at 10°C. How much additional Kl is necessary to saturate the solution?

12. 500 g of water is saturated with KCI at 10°C. If the temperature is raised to 60°C, how much additional KCI is needed to resaturate the solution?

13. What is the average rate of increase in solubility (in g per 100 g H2O per °C) for NaNO3 in the range 10°C -20°C?

14. Which substance shows the largest increase in solubility in the range 30°C -70°C?

15. Which substance is most soluble at 50°C? Which substance is least soluble at 50°C?

16. 100 g of water is saturated with KCIO3 at 70°C. To what temperature must the solution be cooled in order for 10 g of solid to crystallize?

17. Assuming that all of the following can form supersaturated solutions, indicate whether the following solutions are saturated, unsaturated, or supersaturated.

a) 40 g of KCI in 100 g of H₂O at 80°C

b) 120 g of KNO3 in 100 g of H₂O at 60°C

c) 80 g of NaNO3 in 100 g of H₂O at 10°C