1. Which of the following reactions is reversible?

a) Burning of coal
b) Respiration in humans
c) Formation of ammonia (Haber process)
d) Combustion of methane

2. At equilibrium, the concentrations of reactants and products:

a) Keep changing
b) Become zero
c) Remain constant
d) Keep increasing

3. The rate of forward reaction at equilibrium is:

a) Greater than backward reaction
b) Equal to backward reaction
c) Zero
d) Cannot be determined

4. A catalyst affects:

a) Equilibrium constant
b) Speed of reaction
c) Both a and b
d) None of these

5. According to Le-Chatelier’s principle, increasing pressure favors:

a) Side with more moles of gas
b) Side with fewer moles of gas
c) Both sides equally
d) None

6. Which expression represents the equilibrium constant Kc for the reaction: aA + bB ⇌ cC + dD ?

a) [A]^a[B]^b / [C]^c[D]^d
b) [C]^c[D]^d / [A]^a[B]^b
c) [A][B]/[C][D]
d) [C][D]/[A][B]

7. For an exothermic reaction, increasing temperature shifts the equilibrium to the:

a) Right (products)
b) Left (reactants)
c) No change
d) Cannot say

8. Homogeneous equilibrium is when:

a) All species are in the same phase
b) Species are in different phases
c) Only gases are present
d) Only solids are present

9. Which of the following is an example of heterogeneous equilibrium?

a) N2(g) + 3H2(g) ⇌ 2NH3(g)
b) CaCO3(s) ⇌ CaO(s) + CO2(g)
c) H2(g) + I2(g) ⇌ 2HI(g)
d) All of the above

10. The Haber process synthesizes ammonia using which catalyst?

a) Iron
b) Platinum
c) Nickel
d) Palladium