pressure & reversible reactions

• What should you be able to describe by the end of the video on pressure effects in reversible reactions?

  The effective change in the pressure on a reversible reaction at equilibrium
• What happens to a system at equilibrium when changes are made to the conditions?

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

  Le Chatelier's principle
• What is the focus of the video regarding pressure effects?

  The effect of pressure on reversible reactions involving gases
• How does the pressure of a gas depend on the number of molecules?

  The pressure of a gas increases with the number of molecules
• In the example given, how many molecules are present on the left-hand side of the nitrogen and hydrogen reaction?

  Four molecules (one nitrogen and three hydrogen)
• How many molecules are present on the right-hand side of the nitrogen and hydrogen reaction?

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

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

  The equilibrium shifts to the left-hand side
• In the reaction between iodine and hydrogen to form hydrogen iodide, how many molecules are on the left-hand side?

  Two molecules
• In the reaction between iodine and hydrogen, how many molecules are on the right-hand side?

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

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

  • Increasing pressure shifts equilibrium to the side with fewer molecules.
  • Decreasing pressure shifts equilibrium to the side with more molecules.