# Quiz | Chemical Equilibrium

1

Which of the following statements about the equilibrium constant is correct?

According to Le Châtelier's principle, if a dynamic equilibrium is disturbed by changing the conditions, the equilibrium position moves to counteract the change. The quantities whose change may affect an equilibrium are the concentration of a reactant or product, the volume, the pressure and the temperature

2

Which of the following statements is correct?

Chemical equilibrium is a dynamic equilibrium: the forward and reverse reactions still occur but reactants and products are formed at such rate that their concentration does not change

3

What is the equilibrium constant expression KC of the reaction: N(g) + 3 H(g) $⇄$ 2 NH(g)?

Equilibrium constant KC: ratio of product concentrations to reactant concentrations at the equilibrium
The concentrations are raised to a power equal to the stoichiometric coefficient

4

What is the equilibrium constant expression KC of the reaction: 2 ICl (s) $⇄$ I(s) + Cl(g)?

Equilibrium constant KC: ratio of product concentrations to reactant concentrations at the equilibrium
Pure solids reactants and products do not appear in the equilibrium-constant expression (= 1 by convention)

5

How can we increase the total amount of produced Cl2 during the reaction: 2 ICl (s) $⇄$ I(s) + Cl(g)?

According to Le Chatelier’ principle, the position of equilibrium will move in such a way as to counteract the change: by removing the Cl2 as it is formed, the equilibrium will move to the right to produce more Cl2

Additionally, the right is the side with most moles of gas. The equilibrium will move to the right if the concentration of a reactant decreases OR the volume increases OR the pressure decreases

6

What happens when the reaction quotient QC is less than the equilibrium constant K?

Reaction quotient QC: ratio of product concentrations to reactant concentrations at a given time
If QC < K, the reaction will move to the right ⇒ net formation of product