H₂S gas when passed through a solution of cations containing HCl precipitates the cations of the second group in qualitative analysis but not those belonging to the fourth group. It is because: 
 

1.	Presence of HCl decreases the sulphide ion concentration
2.	Presence of HCl increases the sulphide ion concentration
3.	Solubility product of group II sulphides is more than that of group IV sulphides
4.	Sulphides of group IV cations are unstable in HCl

        

The equilibrium constant Br₂ $\rightleftharpoons$2Br at 500 K and 700 K are 10^-10 and 10^-5 respectively. The reaction is:

(a) endothermic                                  (b) exothermic

(c) fast                                               (d) slow

1. a,b

2.c,b

3.a,d

4 c,d

Solubility of a gas in liquid increases on:

1. Addition of a catalyst

2. Increasing the pressure

3. Decreasing the pressure

4. Increasing the temperature

A solution is called saturated if:

1. ionic concentration product < solubility product

2. ionic concentration product > solubility product

3. ionic concentration product $\ge$ solubility product

4. none of the above

The concentration of [H⁺] and concentration of [OH^-] of a 0.1M aqueous solution of 2% ionised weak monobasic acid is                                                                    

[ionic product of water = 1x 10^-14]

1. 0.02x10^-3 M and 5x10^-11 M

2. 1x10^-3 M and 3x10^-11 M

3. 2x10^-3 M and 5x10^-12 M

4. 3x10^-2 M and 4x10^-13 M

The relation for calculating pH of a weak base is:

1. pH =pK_w -1/2 pK_b + 1/2 logc

2. pH =pK_w +1/2 pK_b - 1/2 logc

3. pH =pK_w -1/2 pK_a + 1/2 logc

4. none of the above

In a closed container of 1 dm³, 8 moles of \(AB_3\)​ gas reach equilibrium following the reaction:
\(2 \mathrm{AB}_3(g) \rightleftharpoons \mathrm{~A}_2(g)+3 \mathrm{~B}_2(g)\)
What is the equilibrium constant when 2 moles of \(A_2\) are observed at equilibrium?

1. 72 mol²L^-2                     

2. 36 mol²L^-2 

3. 3 mol²L^-2                       

4. 27 mol²L^-2  

Which is Lewis base?

1. HCl               

2. HNO₃

3. HF               

4. NH₃

For a reversible reaction, if the concentrations of the reactants are doubled, the equilibrium constant will be                                                                                       

1. one-fourth                         

2. halved

3. doubled                             

4. the same

The molecule that is least likely to act as a Lewis base is:     

1. CO         

2. \(F^{-}\)         

3. AlCl₃      

4. PF₃