Free Reversible Reactions MCQs with Answers
52 Reversible Reactions MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
A reversible reaction proceeds in both forward and backward directions, so reactants and products continue changing until dynamic equilibrium is established. The topic covers the meaning of equilibrium, the equality of forward and reverse rates, and how concentration, pressure and temperature disturb equilibrium, which is separate from the rate at which equilibrium is reached.
Last updated
52 questions · page 1 of 3
- A. both reactions have stopped completely
- B. the forward and reverse reactions continue at equal rates
- C. the amounts of reactants and products are equal
- D. all the reactants have been converted to products
Explanation: The word dynamic means both reactions are still running; they simply cancel out, so the concentrations stay constant while molecules…
Correct answer: the forward and reverse reactions continue at equal rates- A. [N2][H2]^3 divided by [NH3]^2
- B. [NH3] divided by [N2][H2]
- C. [NH3]^2 divided by [N2][H2]^3
- D. 2[NH3] divided by [N2] + 3[H2]
Explanation: Kc is written as the product concentrations over the reactant concentrations, each raised to the power of its coefficient in the balanced…
Correct answer: [NH3]^2 divided by [N2][H2]^3- A. the reaction reaches equilibrium very quickly
- B. the reaction is exothermic
- C. the reactants are favoured at equilibrium
- D. the products are strongly favoured at equilibrium
Explanation: Kc compares product to reactant concentrations, so a large value means the equilibrium position lies far to the right and the reaction…
Correct answer: the products are strongly favoured at equilibrium- A. concentration of the reactants
- B. pressure of the system
- C. temperature
- D. the catalyst used
Explanation: Concentration and pressure changes shift the position of equilibrium so that the same value of Kc is restored, and a catalyst affects only…
Correct answer: temperature- A. 1864
- B. 1866
- C. 1888
- D. None of These
Explanation: Guldberg and Waage proposed the law of mass action in 1864, expressing how the rate or equilibrium composition depends on the active…
Correct answer: 1864- A. Kp > kc
- B. Kc > kp
- C. Kp= kc
- D. Kp ≤ kc
Explanation: For gases, Kp = Kc(RT)^Δn, where Δn = total gaseous product moles - total gaseous reactant moles.
Correct answer: Kp= kc- A. Ka
- B. Kb
- C. Kp
- D. K
Explanation: For gaseous equilibria, an equilibrium constant can be written in terms of partial pressures as Kp rather than concentrations as Kc.
Correct answer: Kp- A. high
- B. low
- C. according to Kc
- D. constant
Explanation: At the beginning of a reaction containing reactants, their concentration is taken as high relative to the products, which may initially be…
Correct answer: high- A. dynamic state
- B. static state
- C. free state
- D. unidirectional state
Explanation: Chemical equilibrium is dynamic because the forward and reverse reactions continue simultaneously at equal rates.
Correct answer: dynamic state- A. PCI5 = PCI3 + Cl2
- B. N2 + 3H2 = 2NH
- C. 2CO + O2 = CO2
- D. N2 + O2 = 2NO
Explanation: Kp and Kc are related by Kp = Kc(RT)^delta n, so they have the same numerical value when the change in gaseous moles, delta n, is zero.
Correct answer: N2 + O2 = 2NO- A. No units
- B. Units
- C. Both A & B
- D. None
Explanation: The units of Kc depend on the change in the total number of moles of gaseous or dissolved species in the balanced equation.
Correct answer: Both A & B- A. reactants
- B. acid
- C. base
- D. catalyst
Explanation: A catalyst lowers the activation energy of both the forward and reverse reactions, increasing both rates and allowing equilibrium to be…
Correct answer: catalyst- A. moles2dm+6
- B. moles-2dm+6
- C. moles+2dm-6
- D. Kc may or may not have units
Explanation: For a reaction such as N2 + 3H2 ⇌ 2NH3, delta n = 2 - 4 = -2, so Kc has units of (mol dm-3)^-2 = dm6 mol-2.
Correct answer: Kc may or may not have units- A. reversible
- B. irreversible
- C. spontaneous
- D. non-spontaneous
Explanation: A reversible reaction can proceed in both the forward and backward directions, so reactants form products while products can reform…
Correct answer: reversible- A. Kc is constant at given temperature
- B. Kc is unaffected by change in concentration of reactants or products
- C. Kc indicates the extent of reaction but not about the rate of reaction.
- D. All of the above
Explanation: At a fixed temperature, Kc has a constant value and does not change when equilibrium concentrations are disturbed, although the…
Correct answer: All of the above- A. whole amount of reactant does not change into product
- B. chemical equilibrium is established
- C. a catalyst changes the direction of reaction
- D. rate of forward reaction decreases as reaction proceeds
Explanation: A catalyst does not change the direction or position of equilibrium; it lowers the activation energy for both forward and reverse…
Correct answer: a catalyst changes the direction of reaction- A. BF3
- B. H+
- C. AlCl3
- D. H2O
Explanation: All the given options, BF3, H+, AlCl3, and H₂O, can act as Lewis acids since they can accept electron pairs.
Correct answer: H2O- A. 1
- B. -1
- C. o
- D. -2
Explanation: equilibrium contant are equal when product and reactant number is equal that is deltaN=0
Correct answer: o- A. Chemical pH indicator
- B. Acid/base buffer
- C. Anhydrous solution
- D. Hypotonic solution
Explanation: The term anhydrous is often applied to crystalline substances after the removal of crystallization water.
Correct answer: Anhydrous solution- A. It helps to predict the direction of the reaction
- B. It tells about the extent of the reaction
- C. It tells about the rate of reaction
- D. None of these
Explanation: The equilibrium constant, Kc, is a measure of the ratio of product concentrations to reactant concentrations at equilibrium for a given…
Correct answer: It tells about the rate of reactionReversible Reactions MCQs: common questions
Are these Reversible Reactions MCQs free?
Yes. All Reversible Reactions MCQs from Chemistry are free on TestUstad, with unlimited attempts and no account needed. Nothing on this page is a sample or a trial.
How many Reversible Reactions MCQs are on this page?
There are 52 Reversible Reactions MCQs in the Chemistry bank, shown 20 to a page with the correct answer and an explanation on each.
Does every Reversible Reactions MCQ have an explanation?
Yes. Each Reversible Reactions question shows the correct option and a written explanation of why it is correct, so a wrong answer teaches you something rather than just being marked wrong.
Can I take a timed Reversible Reactions test?
Yes. The practice button on this page starts a free Reversible Reactions test drawn from the Chemistry bank. It marks each answer instantly, gives you a score at the end, and can be retaken as many times as you like.