Equilibrium Flashcards
What is the symbol for a reversible reaction?
What occurs when the a reversible reaction occurs in a closed system?
Dynamic equilibrium
What is dynamic equilibrium?
The relative quantities of reactants and products will reach a certain balance and stay there
Name two examples of reversible reactions
Anhydrous copper(II) sulfate + water ⇔ hydrated copper(II) sulfate
ammonium chloride ⇔ ammonia + hydrogen chloride
What is Le Chatelier’s principle?
If a dynamic equilibrium is distributed by changing the conditions, the positionof equilibrium moves to counteract the change.
How does temperature affect an exothermic reaction?
Increase in Temperature: equilibrium shifts to the left
Descrease in temperature: equilibrium shifts to the right
How does pressure affect a reversible reaction?
Increase in pressure: moves to the place with fewer moles of gas
Decrease in pressure: moves to the place with more moles of gas
What are the properties of Ammonia?
- Compound
- Colourless gas
- Choking gas
- Weak alkali
- Very soluble in water
What are the uses of ammonia?
- Fertilisers
- Explosives
- Nitric acid
What is the manufacture of ammonia called?
The haber process
What are the raw materials in the Haber process and how are they obtained?
Hydrogen - reacting methane and steam or the cracking of oil
Nitrogen- obtaining it from the air using fractional distillation or burning hydrogen in air
What are the conditions for the Haber process?
High temperature - 450oC
High pressure - 200 atmospheres
Iron catalyst
Why do they use a high temperature in the Haber process?
Increases the rate of reaction although it decreases the yield
(Comprimise)
Why is a high pressure used in the Haber process?
There are fewer moles of gas of ammonia so it increases the yield
What affect does a catalyst have?
Increases the rate of reaction without changing the yield of ammonia produced
What is recycled in the Haber process?
Unused hygrogen and nitrogen
What state is ammonia removed from the haber process and how?
Liquid by condensation as it has a higher boiling point than hydrogen and nitrogen
What is the first stage in the production of nitric acid?
Ammonia + Oxygen → Nitrogen monoxide + Water
4 NH3 + 5O2 ⇔ 4 NO + 6 H2O
HIGHLY Exothermic, Platinum Rhodium catalyst
What is the second stage in the manufacture of nitric acid?
Nitrogen monoxide + Oxygen → Nitrogen dioxide
2 NO + O2 → 2 NO2
What is the third stage in the manufacture of nitric acid?
Nitrogen dioxide + Water + Oxygen → Nitric Acid
4 NO2 + O2 + 2 H2O → 4 HNO3
How is the fertiliser ammonium nitrate made?
Nitric acid + Ammonia → Ammonium Nitrate
HNO3 + NH3 → NH4NO3
Why do you add acid to water instead of the other way aorund?
As if you add water to acid then they react and it is not dissapated, no water to hold heat so a acid mist is formed which is very daangerous
What is the manufacture of sulphuric acid called?
The contact process
What are the uses of sulphuric acid?
Paint, ferilisers and detergents
What are the raw materials of the contact process?
Sulphur- desulphurisation of fuels
Air
What occurs at the first stage of the contact process?
Sulphur is burned in air
S + O2 → SO2
What occurs at the second stage in the contact process?
Sulphur dioxide + Oxygen → Sulphur trioxide
SO2 + O2 ⇔ 2 SO3
What conditions are required for the second stage in the contact process?
High temperature 450oC - increases rate of reaction (lowers yield)
Low Pressure 1-2 atm - reduces yield but much cheaper
Vanadium oxide catalyst (V2O5)
Why do you not add suplur trioxide to water?
Creates a dense fog of sulphuric acid
What occurs in the third stage of the contact process
H2SO4 + SO3 → H2S2O7
Sulphuric acid + Sulphur Trioxide → Oleum
THEN
H2S2O7 + H2O → 2H2SO4
Oleum + Water → Sulphuric acid (double concentration)
