Answer to Question #165475 in General Chemistry for Anthony Sahadeo

Question

What is the pH of a 5.50 x 10^-3 M KOH solution?

Answer 1

Answer: 11.81

Explanation:

We'll begin by writing the balanced dissociation equation for KOH. This is given below:

KOH —> K+ + OH-

Next, we shall determine the concentration of Hydroxide ion, [OH-]. This is illustrated below:

From the balanced equation above,

We can see that 1 mole of KOH produced 1 mole of OH-.

Therefore, 6.50x10^-3 M KOH will also produce 6.50x10^-3 M OH-.

Next, we shall determine the pOH of the solution. This is illustrated below:

pOH = –Log [OH-]

[OH-] = 6.50x10^-3 M

pOH = –Log 6.50x10^-3

pOH = 2.19

Finally, we can determine the pH of the solution as follow:

pH + pOH = 14

pOH = 2.19

pH + 2.19 = 14

Collect like terms

pH = 14 – 2.19

pH = 11.81

Therefore, the pH of the solution is 11.81