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pH of a Strong Base

[poll id=”63″]

ANSWER: A. 11

Because this is a strong base, we automatically assume concentration of [OH⁻]=0.001 = 1.0 x 10⁻³.

pOH = -log[OH⁻] = -log[1.0 x 10⁻³] = -(-3) = 3

pH = 14 – pOH

pH = 14 – 3 = 11

Be sure to be familiar and able to calculate logs. You will be expected to without a calculator. The above problem was an easy conversion (likely to be seen), but you may provided with more harder ones (e.x. [OH⁻] = 3.4×10⁻³)