extracting metals and equilibria

Question 1

what do the two arrows over each other going in opposite directions show us

Answer 1

• the reaction goes both ways

Question 2

how can the direction of some reversible reactions be altered

Answer 2

by changing the reaction conditions

Question 3

chemical reaction can be

Answer 3

reversed

Question 4

what is meant by dynamic equilibrium

Answer 4

• when the rate of the forward reaction is equal to the rate of the backward reaction
• at dynamic equilibrium the concentration of reactants and products remains constant

Question 5

describe the formation of ammonia

Answer 5

• a reversible reaction
  -> between nitrogen (extracted from air) and hydrogen (obtained from natural gas)
  -» that can reach a dynamic equilibrium

Question 6

recall the conditions for that Haber process carried out as

Answer 6

• temp 450 degrees
• pressure 200 atmospheres
• iron catalyst

Question 7

predict how the position of dynamic equilibrium is affected by changes in temperature

Answer 7

• decrease the temperature and the equilibrium will move in the exothermic direction to produce more heat
• increasing the temperature makes the equilibrium move in the endothermic direction to absorb extra heat

Question 8

predict how the position of dynamic equilibrium is affected by changes in pressure (only affects equilibria in gases)

Answer 8

• increase pressure = equilibria moves towards the side that has fewer moles of gas to reduce pressure
• decrease pressure = the equilibria will move towards the side that has more moles of gas to increase pressure

Question 9

predict how the position of dynamic equilibrium is affected by changes in concentration

Answer 9

• increase concentration of reactants = equilibria will move to the right to use up the reactant (making more products)
• increase concentration of products = equilibrium will move to the left to use up the products (making more reactants)
• decreasing concentration has the opposite effect