Arrange the following solutions in the decreasing order of pOH:

(A) 0.01 M HCl
(B) 0.01 M NaOH
(C) 0.01 M
(D) 0.01 M NaCl

Question

Arrange the following solutions in the decreasing order of pOH:

(A) 0.01 M HCl
(B) 0.01 M NaOH
(C) 0.01 M 
(D) 0.01 M NaCl

Canvas Classes · Accepted Answer

pOH = 14 − pH. Higher pOH = lower pH = more acidic.

Step 1 — Determine pH of each:

(A) 0.01 M HCl: Strong acid, pH = 2  pOH = 12 (highest pOH)

(B) 0.01 M NaOH: Strong base, pH = 12  pOH = 2 (lowest pOH)

(C) 0.01 M : Salt of weak acid + strong base  basic, pH ≈ 8.4  pOH ≈ 5.6

(D) 0.01 M NaCl: Neutral salt, pH = 7  pOH = 7

Step 2 — Decreasing order of pOH:

Answer: Option (2) — (A)  (D)  (C)  (B)

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