Applications of Equillibrium Flashcards
Define the Haber process.
Industrial process used to make ammonia
What are the 3 uses of ammonia?
Nitric acid
Explosives
Fertiliser
What is the chemical equation for the Haber process?
N2(g) + 3H2(g) <-> 2NH3(g)
Is enthalpy (H) positive or negative in this reaction?
Negative.
Where is the nitrogen gas obtained from in the Haber process?
Fractional distillation of air
Where is the hydrogen gas obtained from in the Haber process?
Cracking of natural gas
What are the 3 reaction conditions for the Haber process?
Iron catalyst - increases the rate of the reaction by lowering the activation energy
Temperature = 450 degrees C - Low enough to favour the exothermic forward reaction, but high enough that the rate is economical
Pressure = 200 atm (or 20000 kPa) - A high enough pressure is needed to favour the forward reaction but not too high as maintaining pressure is very costly
Define the Contact process.
Industrial process to make sulfuric acid. Involves a number of steps, but only step 2 is reversible.
What are the 4 steps of the Contact process?
The combustion/burning/heating of sulfur in air
Formation of Sulfur Trioxide
Formation of Oleum
Formation of Sulfuric Acid
What are the 2 uses of sulfur dioxide?
Bleaching of wood fibres for making paper
Food preservatives
What are the 3 reaction conditions for the Contact process?
Temperature = 450 degrees C - Temperature is low enough that the exothermic forward reaction is favoured but high enough that the yield is still economical
Pressure = 1-2 atm - Pressure is high enough that equillibrium shifts in the direction of the least gas molecules to increase the yield. A pressure higher than that will be too expensive to maintain.
Vanadium Pentoxide / Vanadium (V) oxide catalyst
Describe the Contact process.
The combustion/burning/heating of sulfur in air
Equation: S(s) + O2(g) -> SO2(g)
Formation of Sulfur Trioxide
2SO2(g) + O2(g) <-> 2SO3(g)
Formation of Oleum
SO3 + H2SO4 -> H2S2O7
Formation of Sulfuric Acid
H2S2O7 + H2O -> 2H2SO4
Why can’t water be directly reacted with sulfur trioxide?
Too volatile and toxic gases are produced
What are the 2 uses of sulfuric acid?
Manufacture of paint
Car batteries
