Question

Part D: Problem 29. Consider a O.15 mol/L solution of NaOH a) Calculate the hydroxide ion concentretion. b) Calculate the pOH c) Calculate the pH d) Calculate the hydrogen ion concentration

Answer 1

29(a) In calculation of pH or pOH of acids and bases Normality should be considered, but in the question molarity is given. Let's convert molarity into normality.

Normality=Molarity × Valency

Here valency of NaOH is 1

Normality=0.15×1 = 0.15

This gives the concentration of [OH^-]=0.15mol/l

(b) pOH = [-log(OH^-)]

pOH = [-log(0.15)]

pOH = 0.82

(c) pH+pOH = 14

pH+0.823 = 14

pH = 13.18

(d) pH = [-log(H⁺)]

[H⁺] = 10^-pH

[H⁺] = 10^-13.18

[H⁺] = 6.607

Thank you.