Chem Equilibra Flashcards
State what is meant by ‘dynamic equilibrium’.
Dynamic equilibrium refers to the state of a REVERSIBLE process at which the rates of forwards and backward reactions are EQUAL, but NOT equal to zero.
What are the conditions for the Haber Process? (to produce ammonia) - include temperature, pressure and catalyst
Temperature: 450 deg Celsius
Pressure: 200-250 atm
Catalyst: Finely divided Fe catalyst [with Al2O3 (alumina) and potassium oxide as promoters for Fe catalyst]
Why is a catalyst required for Haber Process?
To speed up the reaction in order to compensate for the relatively low temperature.
How is nitrogen gas obtained for the Haber Process?
It is obtained through fractional distillation of liquid air.
How is hydrogen gas obtained for the Haber Process?
It is obtained from the petroleum industry.
Explain the reasons and consideration behind the temperature for the Haber Process.
Consideration: Very high temperatures are avoided.
- Forward rxn of the process is EXOTHERMIC, hence a lower temp would favour higher yield of ammonia. (POE shifts right to increase temp)
- However, reacting particles need sufficient energy to result in effective collisions among them to form ammonia. Hence a moderately high temperature of 450 deg Celsius is chosen.
Explain the reasons and consideration behind the pressure for the Haber Process
Consideration: High pressures are avoided.
- Mole ratio of reactants to products is 4:2. High pressure would favour the forward reaction to produce higher yield of ammonia.
- However, cost of production will increase since equipment needs to be able to withstand high pressure. Thus, it is carried out at a moderate pressure of about 200-250 atm.
