Question

which is better to neutralize an acid with base of ph 8 or base of ph12 and why

Answer 1

The acid base neutralization take place by the reaction of H+ with OH- and form H2O. So the effectiveness of the base depends on the amount of OH- ions in possess.

Since pH + pOH = 14.

pOH = -log[OH-] , [OH-] = 10^-pOH

For a base with pH = 8, pOH = 14 - 8 = 6

[OH-] = 10^-6 = 1 x 10^-6 M

For a base with pH = 12, pOH = 14 - 12 = 2

[OH-] = 10^-2 = 0.01 M

From this it can be understood that the amount of [OH-] ions in a base with pH = 12 is 0.01 M and at pH = 8 is 0.000001 M, i.e. the [OH-] ion concentration at pH = 12 is 0.01/0.000001 = 10000 times more than that in a base with pH = 8. So a base of pH = 12 will be more effective to neutralize the acid.