What does a solution with higher pH level indicate?

1 Answer
Feb 7, 2017

Answer:

An alkaline solution.

Explanation:

We interrogate the auto-protolysis equilibrium:

#2H_2O rightleftharpoonsHO^(- )+ H_3O^+#

See this old answer. In water, this equilibrium has been carefully measured, such that #K_w=[H_3O^+][HO^-]=10^(-14)# at #298K#.

We classify the acidity of the solution on the #pH# scale, where #pH=-log_10[H_3O^+]#. Given the negative function, numerically higher #pH# values indicate that #[HO^-]# is greater than #10^-7# #mol*L^-1#, and, necessarily, #[H_3O^+]# is LESS than #10^-7# #mol*L^-1#.