revision topic 10 Flashcards
what is a reversible reaction
It is a reaction where the products of a reaction can react with each other to make the original reactants
what are examples of reversible reactions
- the indicator used in a neutralization reaction
- salts and their water crystalazation
- once ammonium chloride is heated
explain how reversible reactions get into equilibrium
it starts out with the rate of reactants being greater than the rate of products, then the rate of products would speed up and the rate of reactions would slow down till eventually, they move at equal rates in equilibrium meaning that there isn’t to change in the amount of product or and reactants
what is a closed system
it is a system where no reactants, products or energy get in or out
what happens at equilibrium
the rate of forward reactions equals the rate of the reverse reactions
in a chemical equilibrium if the amount of reactants decreases making more products available what might happen
the products would start reacting at a faster rate to produce more reactant till equilibrium is restored again
if you increase the pressure on the product side an equilibrium
the pressure on the reactant side would decrease
if the forward reaction produces more gas molecules
an increase in pressure decrease the amount of product formed, and a increase in pressure decrease the amount of product formed
if the forward reaction produces more molecules of gas…
an increase in pressure decreases the amount of products formed, and a decrease in pressure would increase the amount of products formed
if a forward reaction produces fewer gas molecules…
an increase in pressure would lead to an increase of products formed, and a decrease in pressure would lead to a decrease of products formed
if a forward reaction is exothermic…
an increase in temperature decrease the amount of products formed, and a decrease of temperature increases the amount of product formed
if a forward reaction is endothermic…
a decrease in temperature decrease the amount of products formed, and an increase of temperature increases the amount of product formed
why is ammonia important
because it can fertilize plants
what are the raw materials for the productions of ammonia
nitrogen from and the air and hydrogen which we get from natural gas
explain how the Haber process works
the nitrogen and hydrogen are purified, then they are passed over an iron catalyst at a high temperature of 450 and high pressure of 200 this reversible reaction would produce ammonia. in order to extract ammonia we cool down the gas liquefying then removing it from the unreacted hydrogen and nitrogen, then the unrated hydrogen and nitrogen is re-cycled back into the reaction mixture
explain how pressure can affect the production of ammonia
in the reversible reaction to make ammonia you can see that there are more gas molecules in the reactants so if we increase the pressure of the reaction that would produce more ammonia
what are the disadvantages of using high pressure in the ammonia reaction
using high pressures would require a lot of energy and expensive reaction vessels that can withstand a high pressure otherwise there would always be a risk of explosions that why the process is always on 200 atmospheres which is a good compromise
explain how temperature can affect the production of ammonia
so lowering the temperature would increase the amount of ammonia made because the forward reaction is exothermic, however, at low temperatures the rate of reactions would be slow because the gas molecules would collide slower and less energetically, so to balance that out we use a 450c temperature
why is iron important to use
because it is considered a catalyst that would speed up both sides of the reaction meaning that ammonia is made faster
why is sulphuric acid important
because it is used to make paint, pigments, fertilizers, plastics, synthetic fibers, and dye
what are the raw materials for the contact process
sulfur, air, and water
how does the contact process happen
stage 1: sulfur is burnt and oxidized to form sulfur dioxide
stage 2: sulfur dioxide is oxidized again to make sulfur trioxide, then the reaction is at 450c because even though using lower temperature would produce more sulfur trioxide it would slow down the reaction making 450c a good compromise and also we use an atmospheric level of pressure because we have 97% yield using more pressure is a waste of money and also we use vanadium oxide as a catalyst
stage 3: trioxide is mixed with water to form sulfuric acid
