An aqueous solution is found to have a concentration of H3O+ = 2x10-3 M. What is the OH- concentration? Question 9 options: 5x10-12 2x10-3 2x10-11 4x10-6

Question

An aqueous solution is found to have a concentration of H₃O⁺ = 2x10^-3 M. What is the OH^- concentration?

Question 9 options:

	5x10-12
	2x10-3
	2x10-11
	4x10-6

Answer 1

[H₃O⁺][OH^-] = Kw = 1x10^-14 (memorize this)

(2x10^-3)(OH^-) = 1x10^-14

[OH^-] = 1x10^-14 / 2x10^-3

[OH^-] = 5x10^-12

So, your answer of 4x10^-6 would be incorrect. Do you see why?