Equilibrium Constants

Which of the following best describes a reversible chemical reaction?

• A reaction that proceeds in only one direction

• A reaction where the concentrations of reactants and products remain constant

• A reaction that involves different substances as reactants and products

• A reaction that occurs at a constant temperature

Which of the following statements is true about a chemical equilibrium state?

• The concentrations of both reactants and products remain constant

• The reaction stops completely

• The forward reaction rate is faster than the reverse reaction rate

• The temperature increases

Which of the following best describes the reaction N2O4 ⇌ 2NO2?

• Irreversible reaction

• Exothermic reaction

• Endothermic reaction

• Reversible reaction

What is the significance of the double arrow in the reaction equation N2O4 ⇌ 2NO2?

• It indicates an irreversible reaction

• It represents a catalyst in the reaction

• It shows the direction in which the reaction proceed

• It signifies that the reaction is reversible

What happens to the concentrations of N2O4 and NO2 at equilibrium in the reaction N2O4 ⇌ 2NO2?

• Both concentrations increase

• Both concentrations decrease

• The concentration of N2O4 increases, while the concentration of NO2 decreases

• The concentrations of N2O4 and NO2 remain constant

Tags

NGSS.HS-PS1-6

What is the law of mass action?

• The law stating that equilibrium constants remain constant with changing concentrations

• The law stating that the rate of a chemical reaction is directly proportional to the concentration of reactants

• The law stating that the volume of a gas is inversely proportional to its pressure

• The law stating that energy is conserved in a chemical reaction

Tags

NGSS.HS-PS1-5

How can the equilibrium constant be affected by changes in pressure?

• Increasing the pressure will decrease the value of K

• Decreasing the pressure will increase the value of K

• Changes in pressure have no effect on the value of K

• Increasing the pressure will increase the value of K

What is the condition required for chemical equilibrium to be achieved?

• The concentrations of reactants and products must be equal

• The forward reaction rate must be faster than the reverse reaction rate

• The rates of the forward and reverse reactions must be equal

• The temperature must be constant throughout the reaction

Tags

NGSS.HS-PS1-6

What is the key characteristic of a reversible reaction at equilibrium?

• The conversion of reactants into products only

• The conversion of products into reactants only

• The forward and reverse reactions occurring simultaneously

• The absence of any reaction occurring

Tags

NGSS.HS-PS1-6

The equilibrium constant expression for the reaction BrF_5(g) —> Br_2(g) + F_2(g) is

• Kc = [Br₂] [F₂] / [BrF_5]

• Kc = [BrF₅]² / [Br₂][F₂]⁵

• Kc = [Br₂] [F₂]⁵ / [BrF₅]²

• Kc = 2[BrF₅]² / ([Br₂] × 5[F₂]⁵)

• Kc = [Br₂] [F₂]² / [BrF₅]⁵