JEE Chemistry Equilibrium MCQs Set A

Question: Which of the following is not a general characteristic of equilibria involving physical processes ?

• a) All the physical processes stop at equilibrium
• b) The opposing processes occur at the same rate and there is dynamic but stable condition
• c) All measurable properties of the system remain constant
• d) Equilibrium is possible only in a closed system at a given temperature

Answer: All the physical processes stop at equilibrium

Question:  The liquid which has a ………..vapour pressure is more volatile and has a ………….boiling point

• a) Higher, lower
• b) Higher , higher
• c) Lower, lower
• d) Lower, higher

Answer: Higher, lower

Question: Boiling point of the liquid depends on the atmospheric pressure. It depends on the altitude of the place; at high altitude the boiling point

• a) decreases
• b) either decreases or increases
• c) remains same
• d) increases

Answer: decreases

Question: In an experiment three watch glasses containing separately 1mL each of acetone, ethyl alcohol, and water are exposed to atmosphere and the experiment with different volumes of the liquids in a warmer room is repeated, it is observed that in all such cases the  liquid eventually disappears and the time taken for complete evaporation in each case was different. The possible reason is/are

• a)  All of the above
• b) the temperature is different
• c) the amount of the liquids is different
• d) the nature of the liquids is different

Answer: All of the above

Question: A small amount of acetone is taken in a watch glass and it is kept open in atmosphere. Which statement is correct for the given experiment?

• a) The rate of condensation from vapour to liquid state is much less than the rate of evaporation
• b) The rate of condensation from vapour to liquid state is equal or less than the rate of evaporation
• c) The rate of condensation from vapour to liquid state is equal to the rate of evaporation
• d) The rate of condensation from vapour to liquid state is higher than the rate of evaporation

Answer: The rate of condensation from vapour to liquid state is much less than the rate of evaporation

Question: A reaction is said to be in equilibrium when

• a) the rate of transformation of reactant to products is equal to the rate of transformation of products to the reactants.
• b) 50% of the reactants are converted to products
• c) None of these
• d) the volume of reactants is just equal to the volume of the products

Answer: the rate of transformation of reactant to products is equal to the rate of transformation of products to the reactants.

Question:

• a) More water will be formed
• b) Equilibrium will not be formed
• c) Water will evaporate
• d) More ice will be formed

Answer: More water will be formed

Question: Which of the following is not true about a reversible reaction?

• a) Number of moles of reactants and products is always equal
• b) It can be attained only in a closed container
• c) It cannot be influenced by a catalyst
• d) The reaction does not proceed to completion

Answer: Number of moles of reactants and products is always equal

Question: If the synthesis of ammonia from Haber's process is carried out with exactly the same starting conditions (of partial pressure and temperature) but using D₂ (deuterium) in place of H₂. Then

• a) the composition of reaction mixture will remain same at equilibrium.
• b) Use of isotope in reaction will not produce ammonia
• c) At equilibrium rate of forward reaction will be greater than the rate of reverse reaction
• d) the equilibrium will be disturbed

Answer: the composition of reaction mixture will remain same at equilibrium.

Question:

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question: What are the product formed when Deuterium is added equilibrium reaction of H₂ and I₂ ?

(i) HD    (ii) DI
(iii) D2   (iv) HI

• a) All of these
• b) (i) and (ii)
• c) (i), (ii) and (iv)
• d) (ii) and (iv)

Answer: All of these

 More Questions.......................................

Question: If a system is at equilibrium, the rate of forward to the reverse reaction is

• a) equal
• b) at equilibrium
• c) less
• d) high

Answer: equal

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) 6
• b) 36
• c)

  

• d)

  

Answer: 6

Question:

• a) 0.62
• b) 4.5
• c) 2.0
• d) 1.9

Answer:  0.62

Question:

• a) 4
• b)

  

• c)

  

• d) 2

Answer: 4

Question:

• a) Litre mole^–1
• b) Mole litre^–1
• c) Mole litre
• d) No unit

Answer: Litre mole^–1

Question:

• a) 8.0
• b) 0.5
• c) 4.0
• d) 32.0

Answer: 8.0

Question:  In which of the following equilibrium K_c and K_p are not equal?

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question:

• a) (RT)^–1/2
• b) (RT)^–1
• c) (RT)^1/2
• d) (RT)

Answer: (RT)^–1/2

Question:  The K_P/K_C ratio will be highest in case of

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) T = 12.5 K
• b) T = 0 K
• c) T = 1K
• d) T = 273 K

Answer: T = 12.5 K

Question:  Steam reacts with iron at high temperature to give hydrogen gas and Fe₃O₄ (s). The correct expression for the equilibrium constant is

• a)

  

• b)

  

• c)

  

• d) Mo of these

Answer:

Question:

• a) 6.93 atm
• b) 0.693 atm
• c) 6.3 atm
• d) 0.63 atm

Answer: 6.93 atm

Question:

• a) 7.33
• b) 5.33
• c) 4.33
• d) 6.33

Answer: 7.33

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:  Which of the following is an example of homogeneous equilibrium ?

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a)

  

• b)

  

• c)

  

• d)

  

Answer:

Question:

• a) (i), (ii) and (iii)
• b) (i), (iii) and (iv)
• c) (i), (ii) and (iv)
• d) (ii) and (iv)

Answer: (i), (ii) and (iii)

Question: In a reversible chemical reaction having two reactants in equilibrium, if the concentration of the reactants are doubled then the equilibrium constant will

• a) Remain the same
• b) Be halved
• c) Also be doubled
• d) Become one-fourth

Answer: Remain the same

Question: On doubling P and V with constant temperature the equilibrium constant will

• a) remain constant
• b) become one-fourth
• c) become double
• d) None of these

Answer: remain constant

Question:

• a) Reaction proceed backward
• b) Reaction proceed forward
• c) No effect on the formation of product
• d) None of these

Answer: Reaction proceed backward

Question:  If K_c is in the range of ______ appreciable concentrations of both reactants and products are present

• a) 10 ^{– 3} to 10³
• b) 10 ^{– 5} to 10³
• c) 10⁺³ to 10 ^{– 3}
• d) 10^–4 to 10⁴

Answer: 10 ^{– 3} to 10³

Question:

• a) Q > K_c
• b) Q = K_c
• c) Q = 0
• d) Q < Kc

Answer: Q > K_c

Question: The reaction quotient Q is used to

• a) predict the direction of the reaction
• b) calculate equilibrium concentrations
• c) calculate equilibrium constant
• d) predict the extent of a reaction on the basis of its magnitude

Answer: predict the direction of the reaction

Question: The correct relationship between free energy change in a reaction and the corresponding equilibrium constant, K_c is

• a)

  

• b)

  

• c)

  

• d) None of these

Answer:

Question:

• a)

  Both

• b)

  

• c)

  

• d) None of these

Answer:

Both

Question:

• a) I, II and IV are correct
• b) I and IV are correct
• c) II and III are correct
• d) I, II and III are correct

Answer: I, II and IV are correct

Question:

• a) amount of solid to decrease
• b) amount of liquid to decrease
• c) temperature to decrease
• d) temperature to increase

Answer: amount of solid to decrease