CHEMICAL EQUILIBRIUM

The following reaction aA + bB produce cC + dD.

The realtion that determine the equilibirum constant, K_c is known as

• Law of active mass.

• Law of mass action.

• Law of chemical reactions.

• Law of conservation of mass.

Which of the following statements is CORRECT for a reaction at an equilibrium?

• The rate of forward and reverse reactions are equal.

• The final concentrations of product and reactant are equal.

• The initial concentrations of product and reactant are equal.

• The rate constant of the forward and reverse reactions are equal.

For the graph, choose the CORRECT statement.

• The rate of reaction slowly increase

• The systems never reach equilibrium

• At equilibrium, more NO₂ is present than N₂O₄.

• At start of reaction, only NO₂ was present.

Equilibria in which all substances are in the same phases are called

• dynamic equilibrium.

• equilibrium constant.

• homogeneous equilibria.

• heterogeneous equilibria.

For the reaction, choose the CORRECT equilibrium constant, K_c.

• 
• 
• 
• 

From the reaction, choose the CORRECT equilibrium constant, K_p.

• 
• 
• 
• 

Choose the CORRECT sentence to complete the following Le Chatelier's principle.

"If a chemical system at equilibrium is disturbed, the system will..."

• not respond in any way unless a significant change in temperature is made.

• stop the chemical reaction and resume only after the disturbance is removed.

• shift its equilibrium position in the direction that reduces the effect of the disturbance.

• shift its equilibrium position that returns all reactants and products to their original concentrations.

Consider the following reversible reaction, the equilibrium mixture is a PURPLE colour.

According to the Le Chatelier's principle, what will happen to the mixture if concentration HCl is added?

• It will turn blue as [CoCl₄]^2- is being formed

• It will turn pink as more [Co(H₂O)₆]²⁺ is being formed

• It stays purple as addition of HCl has no effect on equilibrium

• it will turn pink as equilibrium position shifts to the right.

What will happen if the total pressure is increase by decreasing the volume?

• No shift in equilibrium will occur.

• Equilibrium shifts to the left, in favour of less number of moles of gas.

• Equilibrium shifts to the right, in favour of more number of moles of gas.

• Equilibrium shifts to both directions because there are equal number of moles of gas.

Choose the CORRECT statement that describes the function of catalyst in chemical equilibrium.

• It increases the amount of product formed.

• It increases the rate at which equilibrium is achieved.

• It changes the value of the equilibrium constant for a reaction.

• It changes the equilibrium position.