Reversible reactions and equilibria Flashcards
describe the reversible reaction of Ammonium chloride: (2)
-a white solid that breaks down when heated, forming ammonia and hydrogen chloride.
-when these two gases are cool enough, they react together to form ammonium chloride again
what is the word and symbol equation for the reversible reactions of ammonium chloride?
Ammonium chloride ⇌ ammonia + hydrogen chloride
NH4Cl(s) ⇌ NH3(g) + HCl(g)
what does this symbol ‘⇌’ mean?
-what is the forward and backwards reaction?
-the reaction is reversible
-the forward reaction is the one that goes to the right
-the backward reaction is the one that goes to the left
what is blue copper sulphate described as?
-what happens once the water is driven off?
hydrated
-blue hydrated copper sulphate is heated, leaving white anhydrous copper sulphate
what does anhydrous mean?
substance containing no water
which conditions are needed reaction achieve dynamic equilibrium? (2)
when it happens in a closed container
-none of the products or reactants can escape
what features of being at equilibrium? (3)
-the forward and backward reactions are still happening
-the rates of the forward and backward reactions are the same
-the concentrations of the reactants and products remain constant (they do not change)
describe the Haber Process: (5)
1- nitrogen (from air) and hydrogen (from natural gas) pumped through pipes
2- a compressor increases the gas pressure to 200 atmospheres
3- the pressurised gases are heated to 450°C and passed through a reaction chamber containing an iron catalyst to speed up the reaction
4- the reaction mixture is cooled so that ammonia liquefies and can be removed
5- unreacted nitrogen and hydrogen are recycled
Explain why iron is used in the Haber process.
it is a catalyst
State the reaction conditions used in the Haber process. (3)
-why are these conditions chosen?
-pressure of 200 atmospheres.
-temperature of 450°C.
-iron catalyst.
to ensure the process of making ammonia is as profitable as possible.
what is the equilibrium position of a reversible reaction?
a measure of the concentrations of the reactants and products at equilibrium.
how can you determine the equilibrium position? (2)
-it is to the left if the concentrations of reactants (left) are greater than the concentration of products (right)
-it is to the right if the concentration of products (right) is greater than the concentrations of reactants (left)
how can the position of equilibrium be changed?
by altering the reaction conditions, such as by changing the:
pressure, concentration and/or temperature
what happens in a reaction involving gas if the pressure is increased?
equilibrium position moves in the direction of the fewest molecules of gas.
what happens in a reaction involving solutions if the concentration of a solute is increased?
equilibrium position moves in the direction away from this solute
