Q. No.An aqueous solution contains 0.10 M H2S and 0.20 M HCl. If the equilibrium constant for the formation of HS– from H2S is 1.0 × 10–7 and that of S2– from HS– ions is 1.2 × 10–13 then the concentration of S2– ions in aqueous solution will be:
1. 5 × 10–8 M
2. 3 × 10–20 M
3. 6 × 10–21 M
4. 5 × 10–19 M
Subtopic: Ionisation Constant of Acid, Base & Salt |
63%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
For a weak acid HA with a degree of dissociation x, which of the following gives the correct expression for \((\text{pH} - \text{pKa})\)?
| 1. | log (1+2x) | 2. | \(\log \left(\dfrac{1-x}{x}\right)\) |
| 3. | 0 | 4. | \(\log \left(\dfrac{x}{1-x}\right)\) |
Subtopic: Ionisation Constant of Acid, Base & Salt |
61%
Level 2: 60%+
JEE
Please attempt this question first.
Hints
Please attempt this question first.
Given that the pH of a 0.1 M solution of acid HQ is 3, the ionization constant \(K_a\) of the acid is:
| 1. | 1 × 10–3 | 2. | 1 × 10–5 |
| 3. | 1 × 10–7 | 4. | 3 × 10–1 |
Subtopic: Ionisation Constant of Acid, Base & Salt |
65%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
At \(\mathrm{298~K},\) The equilibrium constant is \(2 \times10^{15}\) for the reaction: \(\mathrm{Cu}(\mathrm{s})+2 \mathrm{Ag}^{+}(\mathrm{aq}) \rightleftharpoons \mathrm{Cu}^{2+}(\mathrm{aq})+2 \mathrm{Ag}(\mathrm{s})\).
If the equilibrium constant for the reaction \(\frac{1}{2} \mathrm{Cu}^{2+}(\mathrm{aq})+\mathrm{Ag}(\mathrm{s}) \rightleftharpoons \frac{1}{2} \mathrm{Cu}(\mathrm{s})+\mathrm{Ag}^{+}(\mathrm{aq})\) is \(x \times 10^{-8}\), then find the value of \(\mathrm{x}\) in nearest integer form:
1. Eight (8)
2. Five (5)
3. Six (6)
4. Two (2)
If the equilibrium constant for the reaction \(\frac{1}{2} \mathrm{Cu}^{2+}(\mathrm{aq})+\mathrm{Ag}(\mathrm{s}) \rightleftharpoons \frac{1}{2} \mathrm{Cu}(\mathrm{s})+\mathrm{Ag}^{+}(\mathrm{aq})\) is \(x \times 10^{-8}\), then find the value of \(\mathrm{x}\) in nearest integer form:
1. Eight (8)
2. Five (5)
3. Six (6)
4. Two (2)
Subtopic: Ionisation Constant of Acid, Base & Salt |
70%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
What is the number of moles of \(NH_3\) that must be added to \(2L\) of \(0.8~M~AgNO_3\) in order to reduce the concentration of \(Ag^+\) ions to \(5.0 \times 10^{-8} \mathrm{M}\) ? [Assume no volume change on adding \(NH_3]\)
[Given : \(\mathrm{K}_{\text {formation }} \text { for }\left[\mathrm{Ag}\left(\mathrm{NH}_3\right)_2\right]^{+}=1.0 \times 10^8\)]
[Report your answer in the nearest integer]
1. Two (2)
2. Four (4)
3. Eight (8)
4. One (1)
[Given : \(\mathrm{K}_{\text {formation }} \text { for }\left[\mathrm{Ag}\left(\mathrm{NH}_3\right)_2\right]^{+}=1.0 \times 10^8\)]
[Report your answer in the nearest integer]
1. Two (2)
2. Four (4)
3. Eight (8)
4. One (1)
Subtopic: Ionisation Constant of Acid, Base & Salt |
62%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
Sodium oxide reacts with water to produce sodium hydroxide. If \(200 ~\text{g}\) of sodium oxide is dissolved in \(500 ~\text{mL}\) of water, then what is the concentration of the resulting \(\text{NaOH}\) solution?
[Note: Neglect the change in volume]
[Atomic mass; \(\mathrm{Na=23.0,O=16.0,H=1.0]}\)
1. 11
2. 12
3. 13
4. 14
[Note: Neglect the change in volume]
[Atomic mass; \(\mathrm{Na=23.0,O=16.0,H=1.0]}\)
1. 11
2. 12
3. 13
4. 14
Subtopic: Ionisation Constant of Acid, Base & Salt |
Level 3: 35%-60%
Please attempt this question first.
Hints
Please attempt this question first.
Which one of the following compounds will liberate \(\mathrm{CO}_2,\) when treated with \(\mathrm{NaHCO}_3 \text { ? }\)
1. \(\left(\mathrm{CH}_3\right)_3 \stackrel{\oplus}{\mathrm{N}} \mathrm{H} ~\mathrm {Cl^-}\)
2. \(\mathrm{CH}_3 \mathrm{CO} \mathrm{NH}_2 \)
3. \(\mathrm{CH}_3 \mathrm{NH}_2\)
4. \(\left(\mathrm{CH}_3\right)_4 \stackrel{\oplus}{\mathrm{N}}{\mathrm{OH}^-}\)
1. \(\left(\mathrm{CH}_3\right)_3 \stackrel{\oplus}{\mathrm{N}} \mathrm{H} ~\mathrm {Cl^-}\)
2. \(\mathrm{CH}_3 \mathrm{CO} \mathrm{NH}_2 \)
3. \(\mathrm{CH}_3 \mathrm{NH}_2\)
4. \(\left(\mathrm{CH}_3\right)_4 \stackrel{\oplus}{\mathrm{N}}{\mathrm{OH}^-}\)
Subtopic: Ionisation Constant of Acid, Base & Salt |
73%
Level 2: 60%+
Please attempt this question first.
Hints
Determine the concentration of H3O+ ions in a 0.005 M aqueous solution of Ba(OH)2 at 298 K, where Ba(OH)2 is in a fully ionized state.
| 1. | 5 × 10 –12 mol L–1 | 2. | 50 × 10 –12 mol L–1 |
| 3. | 1 × 10 –12 mol L–1 | 4. | 100 × 10 –12 mol L–1 |
Subtopic: Ionisation Constant of Acid, Base & Salt |
69%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
\(0.01\) moles of a weak acid \(HA (K_a = 2.0 × 10^{–6} )\) is dissolved in \(1.0 ~L ~\text{of}~ 0.1~ M~ HCl\) solution. If the degree of dissociation of \(HA\) is \(x × 10^{–5}\) , find the value of \(x\) (rounded off to the nearest integer):
[Note: Neglect volume change on adding \(HA.\)]
1. One (1)
2. Two (2)
3. Three (3)
4. Four (4)
[Note: Neglect volume change on adding \(HA.\)]
1. One (1)
2. Two (2)
3. Three (3)
4. Four (4)
Subtopic: Ionisation Constant of Acid, Base & Salt | Acids & Bases - Definitions & Classification |
71%
Level 2: 60%+
Please attempt this question first.
Hints
Please attempt this question first.
What is the \(\text{pH}\) of \(0.588 ~\text M\) Sulfurous acid \((H_2SO_3)\), if it has \(Ka_1 = 1.7 × 10^{–2}\) and \(Ka_2 = 6.4 × 10^{–8} \)?
1. 1
2. 10
3. 6
4. 13
1. 1
2. 10
3. 6
4. 13
Subtopic: Ionisation Constant of Acid, Base & Salt | pH calculation |
Level 4: Below 35%
Please attempt this question first.
Hints
Please attempt this question first.
© 2026 GoodEd Technologies Pvt. Ltd.