Topic 6 - Reversible Reactions

• What is the contact process?


  The process used to make sulfuric acid from sulfur and water. The sulfur is burned in oxygen to produce sulfur dioxide. The sulfur dioxide then reacts with oxygen, in a reversible reaction, to produce sulfur trioxide. Water is reacted with the sulfur trioxide to finally produce sulfuric acid. The process requires vanadium(V) oxide as a catalyst and is carried out at 450°C temperature and 2 atm pressure.
• What is the effect of concentration on equilibrium?


  If the concentration of a reactant is increased, more products will be formed until equilibrium is reached again. If the concentration of a product is decreased, more reactants will react until equilibrium is reached again.
• What is the effect of pressure on equilibrium?


  An increase in pressure causes the equilibrium position to shift towards the side with the smaller number of moles of gas. A decrease in pressure causes the equilibrium position to shift towards the side with the larger number of moles of gas.
• What is the effect of temperature on equilibrium?


  An increase in temperature will shift the equilibrium position in the direction of the endothermic reaction. A decrease in temperature will shift the equilibrium position in the direction of the exothermic reaction.
• What is a fertiliser?


  A chemical added to soil to increase the fertility, allowing crops to grow more effectively. They generally contain compounds of nitrogen, potassium and phosphorus.
• What is the haber process?


  An industrial process which produces ammonia from the reaction between nitrogen and hydrogen. The reaction conditions are 450°C, 200 atm and an iron catalyst. Hydrogen and nitrogen react together in the following reaction: $3H₂+$$N₂⇌2NH₃$
• What is a reversible reaction?


  A reaction in which the products can react together to reform the reactants. Reversible reactions are denoted by the symbol ⇌.