Pressure and Reversible Reactions

• What happens to a system at equilibrium when conditions change?

  The system responds to counteract the change
• What principle explains the response of a system at equilibrium to changes?

  Le Chatelier's principle
• What is the focus of this video regarding reversible reactions?

  The effect of pressure on reversible reactions
• What does the pressure of a gas depend on?

  The number of molecules in the gas
• How does the number of molecules affect gas pressure?

  More molecules result in higher pressure
• In the reaction of nitrogen and hydrogen to form ammonia, how many molecules are on the left side?

  Four molecules
• In the reaction of nitrogen and hydrogen to form ammonia, how many molecules are on the right side?

  Two molecules
• What happens to the equilibrium position if pressure is increased in a reaction with fewer molecules on the right side?

  The equilibrium shifts to the right side
• What happens to the equilibrium position if pressure is decreased in a reaction with more molecules on the left side?

  The equilibrium shifts to the left side
• In the reaction of iodine and hydrogen to form hydrogen iodide, how many molecules are on both sides?

  Two molecules on each side
• What is the effect of changing pressure on the equilibrium position when the number of molecules is the same on both sides?

  Changing pressure has no effect
• What are the rules regarding pressure effects on reversible reactions?

  • Increase pressure: equilibrium shifts to fewer molecules
  • Decrease pressure: equilibrium shifts to more molecules