If the ph of a solution is increased from ph 5 to ph 7, it means that the a. concentration of h+ is twice (2x) what it was at ph 5. b. concentration of h+ is one–half (1/2) what it was at ph 5. c. concentration of oh– is 100 times greater than what it was at ph 5. selected: d. concentration of oh– is one–hundredth (0.01x) what it was at ph 5.this answer is incorrect. e. concentration of h+ is 100 times greater and the concentration of oh – is one–hundredth what they were at ph 5.

Answer is: Concentration of OH⁻ is 100 times greater than what it was at pH 5.

When pH is below 7, solution is acidic, pH greater that 7 solution is basic and pH equals to 7, solution is neutral.

pH + pOH = 14.

pOH₁ = 14 - 5 = 9; first solution.

pOH₂ = 14 - 7 = 7; second solution.

pOH = -log[OH⁻].

[OH⁻]₁ = 10⁻⁹ M, measure of hydroxide ion (OH⁻) concentration of first solution.

[OH⁻]₂ = 10⁻⁷ M, measure of hydroxide ion (OH⁻) concentration of second solution.

[OH⁻]₂ / [OH⁻]₁ = 10⁻⁷ M / 10⁻⁹ M.

[OH⁻]₂ / [OH⁻]₁ = 100.