Chemistry 30 D1: Chemical Equilibirum

What is the equilibrium-constant expression for 
CO₂(g) + H₂(g) ↔ CO(g) + H₂O(l)

• K_c= [CO][H₂O] / [CO₂][H₂]  
• K_c= [CO₂][H₂] / [CO]
• K_c= [CO₂][H₂] / [CO][H₂O]
• K_c= [CO] / [CO₂][H₂]  

This symbol indicates that a reaction is ____________

• reversible
• irreversible

When the rate of the forward reaction is equal to the rate of backward reaction, the system is said to be in

• Chemical Equilibrium
• Chemical Balance
• Stoichiometry
• Chemical Reaction

Which of the following is NOT true at equilibrium?

• The forward and reverse reactions proceed at the same rate.
• The concentrations of reactants and products do not change.
• The concentration of the reactants is equal to the concentration of the products.
• The forward and reverse reactions continue to occur.

What is the K_eq expression for this reaction?

2 NO_(g) + O_2(g) ⇌ 2 NO_2(g)

• K_eq = [NO₂]² / [NO]² [O₂]

• K_eq = [NO]² [O₂] / [NO₂]²

• K_eq = [NO]² [O₂] [NO₂]²

• K_eq = [NO₂]² / [NO]² + [O₂]

What are [C] and [D]?

• concentration of reactants

• concentration of products

• energy of reactants

• energy of products

At elevated temperatures ammonium carbonate, NH₂COONH₄, is in equilibrium with NH₃ and CO₂ according to the equation;

NH₂COONH₄(s) ↔ 2 NH₃(g) + CO₂(g)

What is the equilibrium expression for this reaction?

• K = 2 [NH₃][CO₂]

  [NH₂COONH₄]

• K = [NH₃]²[CO₂]

  [NH₂COONH₄]

• K = 2 [NH₃][CO₂]

• K = [NH₃]²[CO₂]

An indication that an equilibrium system favours the products is a …

• positive ΔH

• low activation energy

dynamic equilibrium

• condition of continuous, random movement of particles but no overall change in concentration of materials
• the process by which one or more substances change to produce one or more different substances
• a condition where the reaction occurring in a system is completely halted and there exists no movement between the reactants and the products corresponding to the chemical reaction
• a substance that takes part in and undergoes change in a chemical reaction

forward reaction

• the substance that does the dissolving
• the reaction that forms products from reactants
• to produce
• the reaction that forms reactants from products