Chemistry Past year IIT JEE question bank - Chemical Equilibrium

1. The ion that cannot be precipitated by both HCl and H2S is
a. Pb²⁺
b. Ag⁺
c. Cu⁺
d. Sn²⁺

(JEE 1982)

Ans: (d)

2. A certain buffer solution contains equal concentration of X^- and HX. The Kb for X^- is 10^-10. The pH of the buffer is:
a. 4
b. 7
c. 10
d. 14
(JEE 1984)

ans: a

3. A certain weak acid has a dissociation constant of 1.0*10^-4. The equilibrium constant for its reaction with a strong base is:

a. 1.0*10^-4
b. 1.0*10^-10
c. 1.0*10¹⁰
d. 1.0*10¹⁴
(JEE 1984)

Answer: ( c)

4. An example of a reversible reaction is:
(JEE 1985)

5. The conjugate acid of NH₂^- is:

a. NH3
b. NH4OH
c. NH₄⁺
d. N2H4
(JEE 1985)

Answer: (a)

6. the compound that is not a Lewis acid is:

a. BF3
b. AlCl3
c. BeCl2
d. SnCl4
(JEE 1985)

Answer: (c )

BeCl2 cannot accept a lone pair of electrons.


7. the compound whose 0.1 M solution is basic is:

a. ammonium acetate]
b. ammonium chloride
c. Ammonium sulphate
d. sodium acetate
(JEE 1986)

Answer (d)