Question #d19cf

1 Answer
Aug 1, 2017

Because that is how the #pH# scale is defined...........

Explanation:

#pH# stands for #"pouvoir hydrogen"#, the power of hydrogen, based on a logarithmic scale. The hydrogen ion was conceived to be #H^+# or #H_3O^+#, and #pH=-log_10[H_3O^+].#

In the days before calculators, multiplication and division of large and small numbers was simplified by the use of logarithms, and standard tables of logarithms to the #"base e"# and to the #"base 10"# were widely published for use by scientists, and students, and engineers, and also no doubt accountants.