Equilibrium Mock Test – Class 11 Chemistry

1. In the Contact process, is exothermic. Increasing pressure favours formation because

2. When a small amount of strong acid is added to an acidic buffer containing and , the added is mainly consumed by

3. A solution at has . Its is

4. Two statements about are given:
I. At equilibrium, and must have equal concentrations.
II. At equilibrium, the rate of formation of equals the rate of formation of .
The valid choice is

5. A solution of is given. For , at . Taking , the approximate of the salt solution is

6. A graph is drawn for a gas obeying Henry law at fixed temperature, with on the vertical axis and on the horizontal axis. The expected graph is

7. The table gives temperature changes for reversible reactions.

The row that needs correction is

8. A catalyst is added to a reversible reaction already at equilibrium. The catalyst will

9. For a reaction with , the safest conclusion about the equilibrium mixture is that

10. A chemistry record says: “A weak acid buffer is prepared, then a small amount of is added, and later is added to test for .” The two main equilibrium ideas involved are

11. A physical equilibrium can be recognized most safely by

12. A catalyst is added to a reversible reaction mixture before equilibrium is reached. The most suitable effect is that the catalyst

13. A chemical equilibrium mixture is prepared at a fixed temperature from different starting amounts of reactants. The final composition may differ, but the equilibrium condition still requires

14. For , the forward reaction is exothermic. Lowering the temperature favours

15. The autoionization of water is represented as

16. The table gives four equilibria with phase labels.

The pair containing only homogeneous equilibria is

17. In , the conjugate base of is

18. For , . The equilibrium constant for is

19. For , at . Using , is closest to

20. For , the expression for is

21. For , lowering the pressure by increasing volume shifts the equilibrium

22. A saturated solution of a sparingly soluble salt contains undissolved solid at the bottom. The equilibrium is dynamic because

23. For , the value of at a fixed temperature depends on

24. A basic buffer contains and . If and , its at is closest to

25. A mixture of and is an example of

26. A graph description for an exothermic reaction shows that after heating, the concentration of gradually decreases to a new plateau. The forward reaction is most likely

27. A reversible reaction has a very large value of . The most reasonable description of its extent is that

28. The table summarizes precipitation decisions.

The row that needs correction is

29. A student first writes and then forms . The main problem is that

30. A proposed expression for is . The needed correction is

31. Match the physical equilibrium with the pair of opposite processes involved.

32. According to the Arrhenius concept, an acid is a substance that increases the concentration of

33. For , a current mixture has , , and . If , the initial shift is

34. A pressure disturbance graph for shows sudden compression followed by a gradual decrease in the amount of . This is consistent with a shift

35. A sealed reaction vessel contains at equilibrium. The brown colour due to remains constant. This constant colour most directly indicates that

36. A reaction is written as with . A second source writes the same change as . The statement “the first source shows a more product-favoured reaction because ” is weak if the second source has because

37. In , of is taken initially and at equilibrium. If the total pressure is , the partial pressure of is

38. A buffer has high buffer capacity when

39. For , increasing pressure by decreasing volume shifts the equilibrium

40. A reaction begins with only reactants in a closed vessel. As the reaction proceeds toward equilibrium, the forward rate and reverse rate usually change in which way?

41. A comparison of two dissociation equilibria is made:

The two rows with suitable total mole expressions are

42. A saturated solution of has dissolution equilibrium . If the molar solubility is , the solubility product is

43. A larger value of for two weak acids at the same temperature means that the acid with larger

44. A mixture for has current concentrations and . If , the system will initially shift

45. For , of is taken initially. If the degree of dissociation is , the total moles at equilibrium are

46. A reaction has . The equilibrium constant for is

47. For , , with and . The equilibrium concentration of is closest to

48. A graph of vapour pressure of a pure liquid against time in a closed vessel at constant temperature first rises and then becomes horizontal. The horizontal part represents

49. A student pairs with as a conjugate acid-base pair. The pairing is unsuitable because

50. A sample of is mixed with of . The final solution is