Reversible reactions

• What are reversible reactions?

  Reactions where products can form reactants
• How can reversible reactions be represented?

  A + B ⇌ C + D
• What does the symbol ⇌ indicate?

  Reversible reactions with two directions
• What happens to the reaction mixture in reversible reactions?

  It may contain reactants and products
• What occurs when ammonium chloride is heated?

  It breaks down into ammonia and hydrogen chloride
• What is the relationship between exothermic and endothermic reactions in reversible reactions?

  If one is exothermic, the other is endothermic
• What is dynamic equilibrium in reversible reactions?

  Forward and backward reactions occur at the same rate
• What remains constant at equilibrium?

  The concentrations of all reacting substances
• What is the equilibrium position of a reversible reaction?

  A measure of concentrations at equilibrium
• What happens to the equilibrium position if N2 and H2 concentrations are greater than NH3?

  The equilibrium position shifts to the left
• How can the equilibrium position be changed?

  By changing pressure, concentration, or temperature
• What happens to equilibrium if temperature is increased?

  It moves in the endothermic direction
• What occurs if pressure is increased in a gas reaction?

  Equilibrium shifts to the direction of fewer gas molecules
• How many molecules are on the left and right sides of the Haber process equation?

  4 molecules on the left, 2 on the right
• What happens to equilibrium if the forward reaction is exothermic and temperature is increased?

  Equilibrium shifts to the left, reducing ammonia
• What happens if the concentration of a reactant is increased?

  Equilibrium shifts away from that reactant
• What occurs if a product is removed from a reaction?

  Equilibrium shifts to the right to produce more
• What happens when hydrochloric acid concentration is increased in the bismuth chloride reaction?

  Equilibrium shifts to the left, away from HCl