Question

Calculate the [H+] and the [OH−] of a solution with a pH=11.45 at 25 °C

.

calculate the [H+][H+] and the pH of a solution with an [OH−]=0.0063 M at 25 °C.

Calculate the [ OH − ] [OH−] and the pH pH of a solution with an [ H + ]=9.3× 10 −13 M [H+]=9.3×10−13 M at 25 °C

Answer 1

Calculate the [H+] and the [OH−] of a solution with a pH=11.45 at 25 °C

Ans = [H⁺] = 10^-pH = 10^-11.45 = 3.548 X 10^-12 M

[H⁺] = 3.548 X 10^-12

[OH^-] = K_w/ [H⁺]

K_w = 1 X 10^-14

[OH^-] = 1 X 10^-14/3.548 X 10^-12 = 2.818 X 10^-3

[OH^-] = 2.818 X 10^-3

calculate the [H+] and the pH of a solution with an [OH−]=0.0063 M at 25 °C.

[H⁺] = K_w/[OH^-]

K_w = 1 X 10^-14

[H⁺] = 1 X 10^-14/0.0063 = 1.587 X 10^-12 M

[H⁺] =  1.587 X 10^-12 M

pH = -log[H⁺] = -log(1.587 X 10^-12 ) = 11.80

pH = 11.80

Calculate the [OH−] and the pH of a solution with an [ H + ] = 9.3× 10¹³ M

[OH^-] = K_w/ [H⁺]

K_w = 1 X 10^-14

[OH^-] = 1 X 10^-14/9.3 X 10^-13 = 0.01075 M

[OH^-] = 0.01075 M

pH = -log[H⁺] = -log(9.3 X 10^-13 ) = 12.03

pH = 12.03