Concentration change and equilibrium

The video tutorial explains the concept of the reaction quotient QC and its relationship with the equilibrium constant KC. It discusses how the addition of hydrogen gas and hydrogen iodide to a reaction mixture affects chemical equilibrium. The video details how these additions create stress, disturb equilibrium, and how the system responds to restore balance through forward and backward reactions. The tutorial concludes with a summary of how changes in reactant or product concentrations impact the reaction quotient and equilibrium.

What happens to the reaction quotient (QC) when hydrogen gas is added to the reaction mixture?

• QC remains unchanged

• QC decreases and becomes less than KC

• QC increases and becomes greater than KC

• QC becomes equal to KC

How does the system restore equilibrium after hydrogen gas is added?

• By undergoing a backward reaction

• By decreasing the concentration of hydrogen iodide

• By increasing the concentration of iodine

• By undergoing a forward reaction

What is the effect of adding hydrogen iodide to the reaction mixture?

• It increases the QC value

• It decreases the QC value

• It makes QC equal to KC

• It has no effect on QC

When QC is greater than KC, what reaction occurs to restore equilibrium?

• Both forward and backward reactions occur equally

• No reaction occurs

• Forward reaction forming more products

• Backward reaction forming reactants

What is the overall effect of changes in concentration on the reaction quotient?

• It has no effect on QC

• It can either increase or decrease QC

• It always decreases QC

• It always increases QC