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Item 21 refers to the data in the table 23. What is the K value of 2.0 mol dm
-3
w
below NaOH(aq) at 298K?

(A) 2.0 × 1.0 x 10 –14
–14
Gas Equilibrium Partial Pressure (B) 1.0 × 10 /2.0
N a (C) 1.0 × 10 –14
2 (D) 4.0 × 10 –14
H b
2
NH 3 c 24. Which of the following indicators would
be suitable for use in titrating a strong acid
against a weak base?
21. What is the expression for K for the
p
equilibruim N (g) + 3H (g)  2NH (g)? Indicator pH range
3
2
2

(A) c 2 I. Bromophenol blue 2.8 - 4.6
a b II. Methyl red 4.2 - 6.3
3
III. Alizaren yellow 10.1 - 13.0
3
(B) a b (A) I only
c 2 (B) I and II only
(C) II and III only
(C) ab 3 (D) I, II and III
c 2

(D) c 2 25. A buffer solution consists of ethanoic acid
and sodium ethanoate solution.

ab 3
Which equations show how the buffer
maintains constant pH in solution?
22. Which of the following are Bronsted-
Lowry acids? I. CH COO + NH → CH COONO
-
+
3
3
4
II. CH COO + H → CH COOH 4
+
-
3
3
I. NH 4 + III. CH COOH + OH → CH COO + H O
-
-
II. C H OH 3 3 2
5
6
III. CH COO – (A) I and II only
3
(B) I and III only
(A) I and II only (C) II and III only
(B) I and III only (D) I, II and III
(C) II and III only
(D) I, II and III

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