Free Chemical Equilibrium MCQs with Answers
625 Chemical Equilibrium MCQs from Chemistry, each with the correct answer and a written explanation of why it is correct. Free and unlimited, with no account needed.
Reversible reactions reach dynamic equilibrium when forward and reverse rates become equal, and Le Chatelier's principle predicts the effect of changing concentration, pressure or temperature. The chapter also covers solubility product, the common ion effect, buffer action and the conditions used in Haber's process, with equilibrium shifts distinguished from changes in the equilibrium constant.
Last updated
625 questions · page 29 of 32
- A. 30%
- B. 32%
- C. 35%
- D. 33%
Explanation: Remember that in Haber's process, the volume percentage of ammonia in the equilibrium mixture is 35%.
Correct answer: 35%- A. Endothermic
- B. Exothermic
- C. Irreversible
- D. Slow
Explanation: The change in enthalpy of Haber process is negative and there is a release of energy upon completion, therefore, it is "exothermic" and…
Correct answer: Exothermic- A. Law of Mass Action
- B. Catalyst
- C. Le chatelier's Principle
- D. All of these
Explanation: Le Chatelier's principle states that if a dynamic equilibrium is disturbed by changing the conditions, the position of equilibrium shifts…
Correct answer: Le chatelier's Principle- A. Remains unchanged
- B. Changes
- C. Decreases
- D. Increases
Explanation: Option B is correct since Avogadro's law states that under the same conditions of temperature and pressure, equal volumes of different…
Correct answer: Changes- A. Increasing reactant concentrations.
- B. Equal number of reactant and product gas molecules.
- C. Increasing temperature.
- D. Using a catalyst.
Explanation: Increasing the temperature will either increase or decrease the concentration of the reactants or products depending on whether the…
Correct answer: Increasing temperature.- A. Towards the product side
- B. toward the reactant side.
- C. Towards the middle.
- D. None of these
Explanation: When heat is removed, the temperature of the system is lowered, and that favors the exothermic reaction, which, according to Le…
Correct answer: Towards the product side- A. Reaction Mixture.
- B. Reactants.
- C. Equilibrium Mixture.
- D. Products.
Explanation: Le Chatelier's principle is a fundamental principle of chemical equilibrium that predicts the effect of a change in conditions on a system…
Correct answer: Equilibrium Mixture.- A. Reaction Mixture
- B. Reactants
- C. Equilibrium Mixture
- D. Products
Explanation: Option C is correct since Le Chatelier's principle is an observation about the chemical equilibria of reactions.
Correct answer: Equilibrium Mixture569. With different number of moles of reactants and product, what happens to the volume of the system?
- A. It remains unchanged
- B. It changes
- C. It decreases
- D. It increases
Explanation: According to the ideal gas law, PV = nRT, the volume of a gas is directly proportional to the number of moles of gas present (n), assuming…
Correct answer: It changes- A. Liquid state
- B. Solid State
- C. Plasma state
- D. Gaseous state
Explanation: A change in pressure primarily affects substances in the gaseous state.
Correct answer: Gaseous state- A. C(s) + H2O(g) -> CO(g) +2H2(g)
- B. CH3O(l) + CH3CO2H(l) -> CH2CO2CH2(l) + H2O (l)
- C. Cu2+(aq) + 4NH2(aq) -> Cu(NH2)23+ (aq)
- D. N2O4(g) -> 2NO2
Explanation: The units of Kc are dependent upon the number of moles of (only of gases and liquids, not solids like in option A) reactants and products.
Correct answer: CH3O(l) + CH3CO2H(l) -> CH2CO2CH2(l) + H2O (l)- A. Extent of reaction
- B. Direction of reaction
- C. Both A and B
- D. None of the above
Explanation: The explanation for this question will be added soon.
Correct answer: Both A and B- A. KC
- B. K
- C. Kp
- D. None of these
Explanation: Option C is correct since equilibrium constant Kp represents the extent of the forward reaction in terms of the partial pressures of the…
Correct answer: Kp- A. Stability
- B. Reactivity
- C. Compressibility
- D. Instability
Explanation: The equilibrium constant for the decomposition of ozone to oxygen is 1055 at 25°C.2O3 → 3O2 Kc= 1055 at 25°CIt infers that at room…
Correct answer: Instability- A. High
- B. Low
- C. Negligible
- D. None of these
Explanation: The tendency of an irreversible reaction to go in the reverse direction is negligible.
Correct answer: Negligible- A. Maximum
- B. Minimum
- C. Zero
- D. Negligible
Explanation: OPTION A: Maximum is incorrect because, at equilibrium, the rate of the forward and reverse reactions is equal, so there is no net change…
Correct answer: Zero- A. Units
- B. No Units
- C. Both options A and B are correct
- D. A negative value
Explanation: The equilibrium constant formula is kc= concentration of right-hand-side / left-hand-side.
Correct answer: Both options A and B are correct578. When the number of moles of reactants and products are the same, the equilibrium constant will have:
- A. Negative value
- B. Large value
- C. No units
- D. Units
Explanation: OPTION A: A small (negative) Kc value (less than 1) indicates that there are more reactants than products at equilibrium.
Correct answer: No units- A. Kc
- B. K
- C. Kp
- D. None of these
Explanation: Option A is wrong because Kc is not the equilibrium constant for ideal gases in terms of partial pressure.
Correct answer: Kp- A. Reactants over products
- B. Products over reactants
- C. Product times Reactants
- D. None of these
Explanation: At 'equilibrium', the rate of the forward and reverse reactions are equal.
Correct answer: Products over reactants