The Production of Ammonia Flashcards
What is a reversible reaction?
A reaction in which the products of the reaction can themselves react to produce the original reactants.
What is the symbol for a reversible reaction?
A double arrow
What is equilibrium?
When the amounts of reactants and products in a reversible reaction reach a balance - their concentrations stop changing.
What is the rule about reversible reactions in closed systems?
If a reversible reaction takes place in a closed system then a state of equilibrium will always be reached.
What is a closed system?
A system in which none of the reactants or products can escape.
If you raise the temperature of a reversible reaction, what will the effect be on the yield?
The yield of the endothermic reaction will increase.
If you lower the temperature of a reversible reaction, what will the effect be on the yield?
The yield of the exothermic reaction will increase.
If you raise the pressure of a reversible reaction, what will the effect be on the yield?
The yield of the reaction that produces the fewer molecules will increase
If you lower the pressure of a reversible reaction, what will the effect be on the yield?
The yield of the reaction that produced the greater number of molecules increases.
Why don’t catalyst change the equilibrium position of reversible reactions?
They speed up both the forward and backward reactions by the same amount.
What is meant by optimum conditions?
The optimum conditions for a process are those that make the largest amount of the desired product for the smallest input of money, energy and time.
What is the Haber process?
The process by which nitrogen and hydrogen gas are used to make ammonia.
Where does the nitrogen for the Haber process come from?
Air
Where does the hydrogen for the Haber process come from?
Fossil fuels
What is the formula for ammonia production?
N2 + 3H2 -> 2NH3
What conditions are used for the Haber process?
Temperature: 450 degrees
Pressure: 200 atmospheres
Catalyst: Iron
Why is the temperature used during the Haber process 450 degrees?
Because if the temperature is too high then it will favour the backward reaction, but if the temperature is too low then the rate of reaction will be too slow.
Why is the pressure used during the Haber process 200 atmospheres?
Because the higher the pressure the quicker the production of ammonia but if the pressure is too high the plant would be too expensive to make and operate.
Why is an iron catalyst used during the Haber process?
Because it allows the reaction to happen quicker. Without it more energy would be required which would drive the price up.
What state of matter is ammonia from the Haber process?
Liquid
What happens to the nitrogen and hydrogen that doesn’t get used during the Haber process?
They are recycled to reduce waste and costs.
