Chemistry Chapter 6 Entry Test MCQs
Topic 6
1. A reversible reaction shows all of the following characteristic features EXCEPT:
a. Whole reactant does not change into
b. It can proceed in both directions product
c. It is applicable to stoichiometric calculation
d. Chemical equilibrium can establish in it
2. Which equilibrium below is homogeneous?
a. NH4NO3 (s) ⇌ N2O (g) + 2H2O (g)
b. 2CO (g) + O2 (g) ⇌ 2CO2 (g)
c. 2H2O2 (1) ⇌ 2H2O (I) + O2 (g)
d. BaSO4 (s) ⇌ Ba2+ (aq) + SO42- (aq)
3. Chemical equilibrium is not commonly associated:
a. The amount of reactant = The amount of product
b. It is macroscopic property
c. Established from either side of reactant or product
d. It is established in closed system
4. If the reaction A + B → AB. If concentration of A and B are doubled, the rate of reaction will:
a. Increase four times
b. Decrease to one half
c. Decrease to one
d. Increase two times
5. Which one of the following factors can change the value of Kc?
a. Temperature
b. Concentration of reactants
c. Concentration of products
d. Pressure
6. If at equilibrium 1.0 mol A, 2.0 mol B, 6.0 mol C and 20 mol D are present in a 1.0 dm3 vessel, then value of the equilibrium constant is 2A + B ⇌ C + D
a. 30
b. 60
c. 120
d. 1 / 60
7. In which of the following reactions, Kc value has no unit?
a. PCl5⇌ PCl3 + Cl2
b. H2 + I2 ⇌ 2HI
c. 2SO2 + O2 ⇌ 2SO3
d. N2 + 3H2 ⇌ 2NH3
8. Consider the following reaction 2SO2 + O2 ⇌ 2SO3 the unit of Kc is:
a. dm3mol-2
b. mol dm-3
c. dm6mol-2
d. dm3mol
9. In which of the following reactions, heterogeneous equilibrium is established?
a. PCl5 ⇌ PCl3 + Cl2
b. H2 + I2 ⇌ 2HI
c. MgCO3 ⇌ MgO+ CO2
d. N2 + 3H2 ⇌ 2NH3
10. Which one of the following statements is correct about a reaction for which the equilibrium constant is independent of temperature?
a. The enthalpy change is zero
b. The activation energies for both forward and reverse reactions are zero
c. Its rate constants do not vary with temperature
d. There are equal number of moles of reactants and products in it
11. Which one of the following statements is incorrect for Kc?
a. It is associated with ΔH
b. It may or may not have unit
c. It tells us about rate of reaction
d. It depends on equilibrium concentration
12. The equilibrium expression for a reaction is Kc = x2/V(a – x), what is true for this reaction.
a. Decrease of pressure favours backward reaction
b. Increase of pressure favours forward reaction
c. Increase of volume favours backward reaction
d. Decrease of pressure favours forward reaction
13. What is the value of Kc for reaction N2O4 ⇌ 2NO2 if at equilibrium the concentration of N2O4 is 4 × 10-2 mole/dm3 and that of NO2 is 2 × 10-2 mole/dm3
a. 2 × 10-2
b. 1 × 10-2
c. 8 × 10-2
d. 4 × 10-2
14. For the reaction N2 (g) + 2O2 (g) 2NO2 (g), KC= 8.3 × 10-10 at 25oC.
a. 4.8 × 109 M
b. 2.4 × 109 M
c. 2.8 × 109 M
d. 2.8 × 109 M
15. For reaction 3O2 ⇌ 2O3 , the value is:
a. Kp = Kc(RT)+1
b. Kc = Kp
c. Kp = Kc(P/N)-2
d. Kp = Kc(RT)-1
16. In a reaction 2X + Y ⇌ M + N. The concentration of Y is kept constant and that of X is tripled. Now the rate of the reaction will:
a. Decrease by four times
b. Increase nine times
c. Increase four times
d. Be doubled
17. The relationship between Kp and Kc for the following reactions iss H2 + 1/2 O2 ⇌ H2O (g)
a. Kc = Kp (RT)-1/2
b. Kp = Kc√𝑅𝑇
c. Kp = Kc RT
d. Kc = Kp√𝑅𝑇
18. Consider a reaction: C + ½ O2→ CO The Kp/Kc for this reaction is
a. 1/RT
b. RT
c. 1/ (RT)1/2
d. (RT)1/2
19. In a reaction A + B ⇌ C + D when one mole of each of the two reactants are mixed. 0.6 mole of each product is formed. The equilibrium constant calculated is:
a. 0.5
b. 2.25
c. 1.5
d. 1
20. Almost forward reaction is complete when:
a. Moderate Kc Value
b. Kc is very large
c. Can’t determined
d. Kc is very small
21. Value of Kc for the given reaction is 50 at 700 K: H2(g) + I2(g) ⇌ 2HI(g)
When the equilibrium concentration of both reactants is 0.5 M each, the value of Kp under same condition will be:
a. 75
b. 125
c. 100
d. 50
22. Kc value does not depend on all the factors except
a. Concentration
b. Pressure
c. Temperature
d. Catalyst
23. The correct statement about “Kc”
a. depend upon equilibrium concentrations
b. May or may not have a units
c. Thermodynamic property
d. All of the above
24. In which of the following reactions, Kc has moles–2 dm+6 unit
a. PCl5(g) ⇌ PCl3(g) + Cl2(g)
b. N2(g) + 3H2(g) ⇌ 2NH3(g)
c. 2SO2(g) + O2(g) ⇌ 2SO3(g)
d. CH3COOH + C2H5OH ⇌ CH3COOC2H5 + H2O
25. For a reaction A + B⇌ C + D when we start with 2 moles of each A and B, Kc = 25. What will be the value of Kc? If we start with 1 mole of each A and B.
a. 12.5
b. 25
c. 50
d. 5