Law of Mass Action
Chemistry ⇒ Chemical Kinetics and Equilibrium
Law of Mass Action starts at 11 and continues till grade 12.
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Describe how the Law of Mass Action is used to derive the equilibrium constant expression for a general reaction.
Describe the difference between Kc and Kp in the context of the Law of Mass Action.
Describe the role of stoichiometric coefficients in the Law of Mass Action.
Explain why pure solids and pure liquids are not included in the equilibrium constant expression derived from the Law of Mass Action.
For the reaction 2A ⇌ B + C, if the equilibrium concentrations are [A] = 0.2 M, [B] = 0.1 M, and [C] = 0.1 M, calculate Kc.
For the reaction 2NO2(g) ⇌ N2O4(g), if Kc = 4.0 at a certain temperature, and [NO2] = 0.5 M, calculate [N2O4] at equilibrium.
For the reaction 2X ⇌ Y + Z, if Kc = 0.5 and [X] = 0.4 M, [Y] = 0.1 M, calculate [Z] at equilibrium.
For the reaction A + B ⇌ C, if the initial concentrations are [A] = 1.0 M, [B] = 1.0 M, and at equilibrium [C] = 0.6 M, calculate Kc.
Which of the following best describes the Law of Mass Action?
(1) The rate of reaction depends only on temperature.
(2) The rate of reaction is proportional to the product of the concentrations of reactants.
(3) The rate of reaction is independent of concentration.
(4) The rate of reaction is proportional to the sum of the concentrations of reactants.
Which of the following is a correct statement about the Law of Mass Action?
(1) It applies only to gaseous reactions.
(2) It applies to both homogeneous and heterogeneous equilibria.
(3) It applies only to irreversible reactions.
(4) It ignores the stoichiometry of the reaction.
Which of the following is a limitation of the Law of Mass Action?
(1) It does not consider the effect of temperature.
(2) It is not valid for reactions in non-ideal solutions.
(3) It applies to irreversible reactions.
(4) It includes pure solids in the equilibrium expression.
Which of the following is NOT a limitation of the Law of Mass Action?
(1) It does not apply to non-ideal solutions.
(2) It assumes constant temperature.
(3) It applies to all phases equally.
(4) It ignores the effect of catalysts.
Fill in the blank: According to the Law of Mass Action, the equilibrium constant for the reaction N2(g) + 3H2(g) ⇌ 2NH3(g) is Kc = __________.
Fill in the blank: The Law of Mass Action is applicable only to reactions that are __________.
Fill in the blank: The Law of Mass Action is based on the concept of __________ equilibrium.
Fill in the blank: The Law of Mass Action is not applicable to reactions that proceed to __________.
True or False: The Law of Mass Action applies to all chemical reactions, including those that do not reach equilibrium.
True or False: The Law of Mass Action assumes that the system is at equilibrium.
True or False: The Law of Mass Action can be applied to ionic equilibria in aqueous solutions.
True or False: The Law of Mass Action can be used to calculate the equilibrium constant for a reaction at any temperature.
