Industrial Processes Flashcards
What can the ammonia made from the Haber Process be used for?
To make nitric acid, which reacts with ammonia to produce ammonium nitrate, a fertiliser
What are the raw materials needed for the Haber Process?
Air, water and methane
How is nitrogen obtained from the air for use in the Haber Process?
By fractional distillation
How is hydrogen produced for use in the Haber Process?
Methane reacts with steam to form carbon dioxide and hydrogen
What are the conditions needed for the Haber Process?
200atm, 450*C and an iron catalyst
What is a reversible reaction?
A reaction that goes forwards and backwards at the same time
What do reversible reactions reach in a closed system?
An equilibrium
Why is a temperature of 450*C used in the Haber Process, despite meaning a lower % yield of ammonia?
As the forward reaction is exothermic it means that lower temperatures produce a bigger yield, as ammonia molecules start to break up again at higher temperatures. However, the lower temperatures mean that the rate of reaction is very slow, and so 450*C is used
Why is a pressure of 200atm used in the Haber Process?
As the forward reaction produces a smaller number of molecules, a higher pressure means a larger yield of ammonia. However, higher pressures require stronger and more expensive pipes and reaction vessels. Therefore, a medium pressure of 200atm is used
How is nitric acid made?
Ammonia + oxygen –> Nitrogen monoxide + water
Nitrogen monoxide + oxygen –> Nitrogen dioxide
Nitrogen dioxide + water + oxygen –> nitric acid
What catalyst is used when making nitric acid, and at what temperature?
Platinum catalyst at 850*C
Is the reaction when making nitric acid exothermic endothermic?
Exothermic, the heat given out is sufficient to keep the reaction going
What happens to sugar after sulfuric acid is added?
It turns yellow during the reaction, and after is a tall black column of pure carbon
What happens to copper sulfate crystals after sulfuric acid is added?
It forms a white powder on the outside during the reaction, and after breaks down into a white powder
What is a dehydrating agent?
Something that can remove water from compounds
What is the contact process used for?
To make sulfuric acid
What is the first step of the contact process?
Sulphur is burnt in air to form sulphur dioxide
S + O2 –> SO2
What is the second step of the contact process?
Sulphur dioxide is reacted with excess air over a vanadium catalyst at 420*C, at pressures not much over atmospheric to give over 95% conversion to sulphur trioxide
What is the third step of the contact process?
SO3 is absorbed in H2SO4
Is the final reaction of the contact process exothermic or endothermic?
Exothermic
Why is the SO3 absorbed in H2SO4 rather than in water in the contact process?
If water is used to absorb sulphur trioxide, the heat produced would create a corrosive acid smog that is dangerous
What is the Haber Process used for?
To manufacture ammonia from nitrogen and hydrogen
How is oleum formed?
By reacting sulfuric acid with sulfuric trioxide
What is the balanced symbol equation for the formation of oleum?
So2 + H2SO4 –> H2S2O7
Give the balanced symbol equation for the reaction between sugar and sulfuric acid
C12H22O11 + H2SO4 -> 12C + 11H20
