NEET UG - Chemical equilibrium, equilibrium constants Kp and Kc, Le Chatelier's principle, ionic equilibrium, acids and bases concepts, pH scale, buffers and solubility products Online Test (MCQ Quiz)

1. For a reversible reaction, which statement is always true at equilibrium?

A) The rate of the forward reaction is equal to the rate of the reverse reaction. B) The concentrations of reactants and products are equal. C) The reaction has stopped. D) The temperature and pressure are constant.

2. In the equilibrium N2(g) + 3H2(g) <=> 2NH3(g), if the partial pressure of N2 is increased, what will happen to the equilibrium?

A) Shift to the left (towards reactants) B) Shift to the right (towards products) C) No change D) The equilibrium constant will change

3. The equilibrium constant Kc for the reaction aA + bB <=> cC + dD is given by:

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

4. For the reaction PCl5(g) <=> PCl3(g) + Cl2(g), if the volume of the container is decreased, the equilibrium will:

A) Shift to the left B) Shift to the right C) Remain unchanged D) The equilibrium constant will increase

5. Which of the following is a unit of Kc for the reaction H2(g) + I2(g) <=> 2HI(g)?

A) mol/L B) mol^-1 L C) mol L^-1 D) Unitless

6. Le Chatelier's principle applies to:

A) Systems at equilibrium B) Systems not at equilibrium C) Only gaseous reactions D) Only exothermic reactions

7. For an endothermic reaction at equilibrium, if the temperature is increased, the equilibrium will:

A) Shift to the left B) Shift to the right C) Remain unchanged D) The equilibrium constant will decrease

8. The relationship between Kp and Kc for the reaction N2(g) + 3H2(g) <=> 2NH3(g) is:

A) Kp = Kc(RT)^-2 B) Kp = Kc(RT)^2 C) Kp = Kc D) Kp = Kc(RT)

9. Adding a catalyst to a reversible reaction at equilibrium:

A) Shifts the equilibrium to the right. B) Shifts the equilibrium to the left. C) Increases the rate of both forward and reverse reactions equally, reaching equilibrium faster. D) Decreases the equilibrium constant.

10. Which of the following is a characteristic of ionic equilibrium?

A) It involves reactions between ions in solution. B) It only occurs in non-polar solvents. C) It does not involve dynamic processes. D) It is always fast.

11. According to Arrhenius theory, an acid is a substance that:

A) Donates a proton (H+) B) Accepts a proton (H+) C) Dissociates in water to produce H+ ions D) Dissociates in water to produce OH- ions

12. A Brønsted-Lowry base is defined as a species that:

A) Accepts a proton B) Donates a proton C) Donates an electron pair D) Accepts an electron pair

13. The pH of a neutral solution at 25°C is:

A) 0 B) 7 C) 14 D) 1

14. A solution with a pH of 3 is considered:

A) Acidic B) Basic C) Neutral D) Amphoteric

15. What is the pOH of a solution with a pH of 10?

A) 4 B) 10 C) 14 D) 0

16. For a strong acid like HCl, its dissociation in water is:

A) Partial B) Complete C) Reversible D) Slow

17. Which of the following is a conjugate acid-base pair?

A) H2O and OH- B) HCl and Cl- C) NH3 and NH4+ D) All of the above

18. A buffer solution resists changes in pH upon addition of small amounts of:

A) Strong acid or strong base B) Weak acid or weak base C) Salt D) Water

19. A buffer solution is typically made from a mixture of:

A) A strong acid and its conjugate base B) A strong base and its conjugate acid C) A weak acid and its conjugate base D) A weak base and its conjugate acid

20. The Henderson-Hasselbalch equation for a weak acid buffer is:

A) pH = pKa + log([conjugate base]/[acid]) B) pH = pKa + log([acid]/[conjugate base]) C) pOH = pKb + log([conjugate acid]/[base]) D) pH = pKa - log([acid]/[conjugate base])

21. The solubility product (Ksp) of a sparingly soluble salt like AgCl is:

A) [Ag+][Cl-] B) [Ag+][Cl-]/[AgCl] C) [Ag+]/[Cl-] D) [Ag+] + [Cl-]

22. If the ionic product of a solution is greater than its Ksp, then:

A) Precipitation will occur B) No precipitation will occur C) The solution is unsaturated D) The salt is highly soluble

23. The common ion effect states that the solubility of a sparingly soluble salt is decreased by the presence of:

A) A common ion B) An ion not common to the salt C) Water D) An acid

24. The autoionization of water produces:

A) H+ and OH- ions B) H3O+ and OH- ions C) Only H+ ions D) Only OH- ions

25. Which of the following is an example of a Lewis acid?

A) BF3 B) NH3 C) H2O D) OH-

26. The conjugate base of H2SO4 is:

A) HSO4- B) SO4^2- C) H3O+ D) OH-

27. For the equilibrium CO(g) + H2O(g) <=> CO2(g) + H2(g), if the concentration of CO is increased, the equilibrium will:

A) Shift to the left B) Shift to the right C) Remain unchanged D) The equilibrium constant will decrease

28. A solution with a pOH of 2 is:

A) Acidic B) Basic C) Neutral D) Strongly acidic

29. Which factor does NOT affect the equilibrium position of a gaseous reaction?

A) Temperature B) Pressure C) Concentration of reactants/products D) Addition of an inert gas at constant volume

30. The equilibrium constant Kp is defined in terms of:

A) Molar concentrations B) Partial pressures C) Mole fractions D) Total pressure

31. For the reaction 2SO2(g) + O2(g) <=> 2SO3(g) (exothermic), if temperature is decreased, equilibrium will:

A) Shift to the left B) Shift to the right C) Remain unchanged D) The rate of reaction will decrease

32. The ionization constant of a weak acid (Ka) is:

A) The equilibrium constant for its dissociation B) The equilibrium constant for its association C) The solubility product D) The concentration of H+ ions

33. Which of the following is a strong base?

A) NH3 B) NaOH C) CH3COOH D) H2O

34. The pH of a 0.01 M HCl solution is:

A) 1 B) 2 C) 12 D) 13

35. A buffer solution of acetic acid and sodium acetate has a pH of 4.75. If Ka for acetic acid is 1.8 x 10^-5, what is the ratio of [CH3COO-]/[CH3COOH]?

A) 1:1 B) 1:2 C) 2:1 D) 10:1

36. The solubility of CaF2 is 's' mol/L. Its solubility product Ksp is:

A) 4s^3 B) s^2 C) s^4 D) 2s

37. Which of the following will decrease the solubility of AgCl in water?

A) Adding NaCl solution B) Adding AgNO3 solution C) Adding pure water D) Heating the solution

38. The Lewis acid-base reaction involves the transfer of:

A) A proton B) An electron pair C) A neutron D) An electron

39. What is the concentration of H+ ions in a solution with pH = 5?

A) 10^-5 M B) 5 M C) 10^5 M D) 0.5 M

40. For the reaction SO2Cl2(g) <=> SO2(g) + Cl2(g), if the pressure is increased by doubling the volume, the equilibrium will:

A) Shift to the left B) Shift to the right C) Remain unchanged D) The equilibrium constant will change

41. In an ionic equilibrium, the degree of dissociation of a weak electrolyte is:

A) Directly proportional to the square root of dilution B) Inversely proportional to the square root of dilution C) Independent of dilution D) Directly proportional to dilution

42. Which of the following is an amphoteric substance?

A) HCl B) NaOH C) H2O D) NH3

43. The Ksp of Mg(OH)2 is 1.8 x 10^-11. The solubility of Mg(OH)2 in pure water is:

A) 2.6 x 10^-4 M B) 1.3 x 10^-4 M C) 1.8 x 10^-11 M D) 3.6 x 10^-11 M

44. If Kp > Kc for a reversible reaction, it implies that:

A) Δn > 0 (change in moles of gas is positive) B) Δn < 0 (change in moles of gas is negative) C) Δn = 0 (change in moles of gas is zero) D) The reaction is exothermic

45. A buffer solution prepared from a weak base and its conjugate acid will have its pH calculated using:

A) pH = pKa + log([base]/[acid]) B) pOH = pKb + log([conjugate acid]/[base]) C) pH = pKb + log([base]/[acid]) D) pOH = pKa + log([acid]/[base])

46. The solubility of a salt is defined as:

A) The maximum amount of solute that can dissolve in a given amount of solvent at a specific temperature. B) The rate at which a solute dissolves. C) The equilibrium concentration of the dissolved solute. D) The total amount of solute present in a solution.

47. Which of the following species can act as both a Brønsted-Lowry acid and a Brønsted-Lowry base?

A) H2SO4 B) OH- C) NH3 D) HCO3-

48. For the equilibrium CaCO3(s) <=> CaO(s) + CO2(g), if the pressure of CO2 is increased, the equilibrium will:

A) Shift to the left B) Shift to the right C) Remain unchanged D) The equilibrium constant will increase

49. The pH of a 0.001 M NaOH solution is:

A) 3 B) 11 C) 14 D) 1

50. If the ionic product of a solution is less than its Ksp, the solution is:

A) Unsaturated B) Saturated C) Supersaturated D) At equilibrium

Chemical equilibrium, equilibrium constants Kp and Kc, Le Chatelier's principle, ionic equilibrium, acids and bases concepts, pH scale, buffers and solubility products - Online Test

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