Equilibrium Mock Test – Class 11 Chemistry

1. Adding to a saturated solution decreases the solubility of because

2. The same species can sometimes act as either an acid or a base. A suitable example is

3. For , a solution has at equilibrium. Taking , is

4. A concentration-time graph for shows decreasing and increasing. After some time, both curves become horizontal. The horizontal region means that

5. An inert gas is added to a gaseous equilibrium mixture at constant pressure. The volume increases, and the reacting gases are diluted. The shift, if any, is predicted by

6. Selective precipitation is possible when

7. For , if the molar solubility is , the correct relation between and is

8. A solution of is prepared. If and , the approximate at is

9. A salt solution undergoes hydrolysis when

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

11. A small value of for a reversible reaction should be interpreted as

12. A solution contains and with and . If , the solution is

13. A catalyst is added to an equilibrium mixture and a rate-time graph is recorded. Immediately after addition, the best graph description is

14. Use the table to identify the set that matches an equilibrium state.

15. A weak acid has . A buffer is prepared with and . The hydrogen ion concentration predicted from is

16. In the reaction , the acid-base roles are

17. If for a sparingly soluble salt in water, the solution is best described as

18. is commonly classified as a Lewis acid because it can

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

20. A reversible reaction has at a fixed temperature. This value most directly suggests that

21. A conductivity test is performed on equal-concentration aqueous solutions. One solution lights the bulb brightly, another lights it dimly, and a third does not light it. The most suitable classification is

22. A reaction has for . The value of for and for , respectively, is

23. A mixture has for a reversible reaction at fixed temperature. The best conclusion is that

24. Assertion: Adding a product to an equilibrium mixture at fixed temperature can make the reaction shift in the reverse direction.
Reason: Adding product makes the reaction quotient larger than the equilibrium constant for many product-over-reactant expressions.

25. For , at a temperature . The symbolic expression for is

26. A metal hydroxide has . If , the needed to just begin precipitation is

27. A solution of in water is acidic under the Arrhenius concept because

28. An ICE setup for starts with of and no . If is the concentration of dissociated, the equilibrium concentrations are

29. For a reversible reaction at equilibrium, the forward rate is . The reverse rate at the same instant is

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

31. Assertion: Increasing temperature favours the endothermic direction of a reversible reaction.
Reason: The endothermic direction absorbs heat supplied to the system.

32. Assertion: At equilibrium, the forward and reverse reactions continue.
Reason: At equilibrium, the forward and reverse rates are equal.

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

34. A statement about physical equilibrium says: “At equilibrium, the measurable property is constant because the forward physical process has stopped.” The better correction is that

35. Ostwald dilution law for a weak acid is based on the equilibrium

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 a closed vessel containing liquid water and its vapour, the measurable property that becomes constant at fixed temperature is

38. A gas equilibrium has , , and at equilibrium. The value of is

39. A weak acid is diluted from to at the same temperature. If remains constant, the approximate degree of ionization changes by a factor of

40. At , a salt of a weak acid and weak base may use the relation . If and , the solution is expected to be

41. In , the conjugate base of is

42. The table summarizes precipitation decisions.

The row that needs correction is

43. For the weak acid equilibrium and the salt equilibrium , adding will usually

44. For , . The equilibrium constant for is

45. A claim about equilibrium says, “The reaction has finished because the composition is constant.” The better interpretation is that

46. Consider the following statements about and :
I. A larger generally corresponds to a more negative .
II. If , then is positive for the written reaction.
III. At equilibrium, , but need not be zero.

47. A compact summary for precipitation, buffer action, and weak electrolyte ionization is most accurate when it says

48. In the notation , the arrow shows that

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

50. An equilibrium concentration table for gives and . The value of is