EXP. A rough idea of the difference in the chemical actions of the two bases may be obtained by observing their effects on the ester, methyl acetate, which is decomposed into an acetate and methyl alcohol rather rapidly. To 50 c.c. of (CO_{2} free) water containing some phenolphthaleïn, 10 c.c. of 0.1 molar potassium hydroxide is added; a similar mixture with 10 c.c. of 0.1 molar ammonium hydroxide solution is prepared. To each of the solutions, 2 c.c. (an excess) of methyl acetate is added (to the ammonium hydroxide solution first), and the mixtures are shaken for a moment. At room temperature, the mixture containing potassium hydroxide will become pale pink in a few minutes, and colorless soon thereafter, while the mixture [p081] containing ammonium hydroxide will still be deep red at the end of 45 minutes.[141] In the following tables are summarized some of the results which have been obtained in comparing the ‹activity of bases›, in saponifying methyl acetate, and ‹the concentrations of the hydroxide-ion›, in the solutions of the bases, as determined by conductivity measurements. The comparisons are made by representing the activity of the hydroxide-ion in a solution of lithium hydroxide by 100 and by expressing the ratio of the activity of a given base to that of the lithium hydroxide in percentages of the activity of the latter. All the bases were used in 0.025 molar concentration, and their degrees of ionization are given in the last column of the table. CHEMICAL ACTIVITY OF BASES AND THEIR IONIZATION[A] Relative Base. Activity. Concentration of HO^{−}. Lithium hydroxide 100 97 Potassium hydroxide 98 97 Sodium hydroxide 98 97 Ammonium hydroxide 2 2.5 Ethyl ammonium hydroxide 12 16. TABLE NOTE: A. Whetham, ‹Theory of Solutions›, p. 338 (1902). (‹Cf.› Walker, ‹Introduction to Physical Chemistry›, p. 277 (1899).)