which one is most basic, the H+ concentration = 1.0 times 10 to the power of -11 or...?

Question

and OH-= 1.0 times 10 to the power of -14

Answer 1

Convert them both to the pH scale.

pH = -log[H+]

if [H+] = 1 x 10^-11, then the pH is 11 (basic)

pOH = -log[OH-] and pOH + pH = 14

if [OH-] = 1 x 10^-14, then the pOH is 14

Since pOH + pH = 14, the pH of the second example is 0. The higher the pH the more basic the solution. The first example is more basic.