7. Account for the fact that sugar sometimes deposits from molasses, even when no evaporation has taken place.
8. (a) From the standpoint of the theory of electrolytic dissociation, write the simple equation for a dilute solution of copper sulphate (CuSO4); this solution is blue. (b) In the same manner, write one for sodium sulphate; this solution is colorless. (c) How would you account for the color of the copper sulphate solution?
9. (a) As in the preceding exercise, write a simple equation for a dilute solution of copper chloride (CuCl2); this solution is blue. (b) In the same manner, write one for sodium chloride; this solution is colorless. To what is the blue color due?
10. What component is present in concentrated sulphuric acid that is almost wanting in very dilute sulphuric acid?
11. Why will vegetables cook faster when boiled in strong salt water than when boiled in pure water?
12. How do you explain the foaming of soda water?