The first and second dissociation constants of an acid H₂A are 1.0 × 10^–5 & 5.0 × 10^–10 respectively. The overall dissociation constant of the acid will be :

1.	5.0 × 10–5	2.	5.0 × 1015
3.	5.0 × 10–15	4.	0.2 × 105

In a saturated solution of the sparingly soluble electrolyte AgIO₃ (molecular mass = 283) the equilibrium is represented by–
${\mathrm{AgIO}}_3\left(\mathrm{(s)}\right)\rightleftharpoons {\mathrm{Ag}}^{+}\left(\mathrm{(aq)}\right)+<mspace\; width="1em"></mspace>{{\mathrm{IO}}_3}^{-}\left(\mathrm{(aq)}\right)$
If the solubility product constant K_sp of AgIO₃ at a given temperature is 1.0 × 10^-8, Calculate the mass of AgIO₃ contained in 100 ml of its saturated solution.

1. 28.3 × 10^–2 g

2. 2.83 × 10^–3 g

3. 1.0 × 10^–7 g

4. 1.0 × 10^–4 g

The pKa of a weak acid (HA) is 4.5. The pOH of an aqueous buffered solution of HA in which 50 % of the acid is ionized is:

1. 4.5

2. 2.5

3. 9.5

4. 7.0
 

The equilibrium constants, \(\mathrm{Kp}_1 \text { and } \mathrm{Kp}_2\) for the reactions \(\mathrm{X} \rightleftharpoons 2 \mathrm{Y} \text { and } \mathrm{Z} \rightleftharpoons \mathrm{P}+\mathrm{Q},\) are given as 1:9.
Assuming equal degrees of dissociation for both X and Z, what is the ratio of total pressures at equilibrium?

1. 1 : 1

2. 1 : 3

3. 1 : 9

4. 1 : 36

For the three reactions (a, b, and c) listed below, the equilibrium constants are provided:

(a). CO(g) + H₂O(g) ⇌ CO₂(g) + H₂(g);  K₁    
(b). CH₄(g) + H₂O(g) ⇌ CO(g) + 3H₂(g); K₂    
(c). CH₄(g) + 2H₂O(g) ⇌ CO₂(g) + 4H₂(g); K₃

Which of the following relations is correct?

1. ${\mathrm{K}}_2{\mathrm{K}}_3={\mathrm{K}}_1$

2. ${\mathrm{K}}_3={\mathrm{K}}_1{\mathrm{K}}_2$

3. ${\mathrm{K}}_3{\mathrm{K}}_2^3={\mathrm{K}}_1^2$

4. ${\mathrm{K}}_1\sqrt{{\mathrm{K}}_2}={\mathrm{K}}_3$

The pK_a of a weak acid HA, is 4.80. The pK_b of a weak base BOH, is 4.78. The pH of an aqueous solution of the corresponding salt, BA, will be: 

1. 4.79

2. 7.01

3. 9.22

4. 9.58

The exothermic formation of ClF₃ is represented by the equation:
${\mathrm{Cl}}_2\left(\mathrm{g}\right)+3{\mathrm{F}}_2\left(\mathrm{g}\right)<mspace\; width="1em"></mspace>\rightleftharpoons <mspace\; width="1em"></mspace>2<mspace\; width="1em"></mspace>{\mathrm{ClF}}_3\left(\mathrm{g}\right);<mspace\; width="1em"></mspace>∆\mathrm{Hr}=-329<mspace\; width="1em"></mspace>\mathrm{kJ}$
Which of the following will increase the quantity of ClF₃ is an equilibrium mixture of Cl₂, F₂ , and ClF₃?

1. Adding F₂

2. Increasing the volume of the container

3. Removing Cl₂

4. Increasing the temperature

An amount of solid NH₄HS is placed in a flask already containing ammonia gas at a certain temperature and 0.50 atm pressure. Ammonium hydrogen sulphide decomposes to yield NH₃ and H₂S gases in the flask. When the decomposition reaction reaches equilibrium, the total pressure in the flask rises to 0.84 atm? The equilibrium constant for NH₄HS decomposition at this temperature is:

1. 0.11

2. 0.17

3. 0.18

4. 0.30

In a closed reaction vessel, Phosphorus pentachloride dissociates as follows:

\(\mathrm{PCl}_{5}(g) \rightleftharpoons \mathrm{PCl}_{3}(g)+\mathrm{Cl}_{2}(g)\)

If the total pressure at equilibrium of the reaction mixture is P and the degree of dissociation of PCl₅  is x, the partial pressure of PCl₃ will be:

1. \(\left(\frac{x}{x+1}\right) P\)

2. \(\left(\frac{2x}{x-1}\right) P\)

3. \(\left(\frac{x}{x-1}\right) P\)

4.  \(\left(\frac{x}{1-x}\right) P\)

The conjugate base of \(H_2PO_{4}^{-}\) is:

1. \(PO_{4}^{3-}\)

2. \(P_2O_5\)

3. \(H_3PO_4\)

4. \(HPO_{4}^{2-}\)