Answer to Question #310107 in Chemistry for lerato

Question

What is the (a) H+ ion concentration, (b) pH, (c) OH- ion concentration and (d) pOH of a 0.001 M solution of NaOH?

Answer 1

NaOH is a strong base because NaOH completely dissociates into sodium (Na⁺) and hydroxide (OH⁻) ions in aqueous solutions. 

Equation representing the dissociation of NaOH:

NaOH(aq) → Na⁺(aq) + OH⁻(aq)

The molarity of NaOH is 0.001 M

C_M(NaOH) = [OH⁻] = [Na⁺] = 0.001 M

Thus,

[OH⁻] = 0.001 M

pOH = −log[OH⁻] = −log[0.001] = 3

pH = 14 − pOH = 14 − 3 = 11

[H⁺] = 10^−pH = 10⁻¹¹ = 1.0×10⁻¹¹ M

Answer:

(a): [H⁺] = 1.0×10⁻¹¹ M

(b): pH = 11

(c): [OH⁻] = 0.001 M

(d): pOH = 3