Reversible reactions and Equilibria.

• Chemical reactions are reversible, the use of the symbol ⇌ in equations and the direction of some reversible reactions can be altered by changing the reaction conditions.
• A forward arrow represents the formation of products from reactants, while a backward arrow represents the reverse process.
• Dynamic equilibrium is a state in a reversible chemical reaction where the rate of the forward reaction is equal to the rate of the reverse reaction.
• The formation of ammonia is a type of reversible reaction between nitrogen (extracted from the air) and hydrogen (obtained from natural gas). It can reach dynamic equilibrium. N2 + 3H2 ⇌ 2NH3.
• What is the Haber process?

  The process of preparing ammonia from nitrogen and hydrogen.
• What are the conditions of the Haber process?

  Temperature: 450 C

  Pressure: 200 atm

  An Iron catalyst is needed.
• Le Chatelier's principle states that if there's a change in concentration, pressure, or temperature in a reversible reaction, the equilibrium position will move to help counteract that change.
• 1. If you decrease the temperature, the equilibrium will move in the exothermic direction to produce more heat.2) If you increase the temperature, the equilibrium will move in the endothermic direction to absorb the extra heat.
• 1. If you increase the pressure, the equilibrium will move towards the side that has fewer moles of gas to reduce pressure. 2) If you decrease the pressure, the equilibrium will move towards the side that has more moles of gas to increase pressure.
• 1)If you increase the concentration of the reactants, the equilibrium will move to the right to use up the reactants (making more products).2) If you increase the concentration of the products, the equilibrium will move to the left to use up the products (making more reactants).3) Decreasing the concentration will have the opposite effect.