revision topic 10

Question 1

what is a reversible reaction

Answer 1

It is a reaction where the products of a reaction can react with each other to make the original reactants

Question 2

what are examples of reversible reactions

Answer 2

1. the indicator used in a neutralization reaction
2. salts and their water crystalazation
3. once ammonium chloride is heated

Question 3

explain how reversible reactions get into equilibrium

Answer 3

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

Question 4

what is a closed system

Answer 4

it is a system where no reactants, products or energy get in or out

Question 5

what happens at equilibrium

Answer 5

the rate of forward reactions equals the rate of the reverse reactions

Question 6

in a chemical equilibrium if the amount of reactants decreases making more products available what might happen

Answer 6

the products would start reacting at a faster rate to produce more reactant till equilibrium is restored again

Question 7

if you increase the pressure on the product side an equilibrium

Answer 7

the pressure on the reactant side would decrease

Question 8

if the forward reaction produces more gas molecules

Answer 8

an increase in pressure decrease the amount of product formed, and a increase in pressure decrease the amount of product formed

Question 9

if the forward reaction produces more molecules of gas…

Answer 9

an increase in pressure decreases the amount of products formed, and a decrease in pressure would increase the amount of products formed

Question 10

if a forward reaction produces fewer gas molecules…

Answer 10

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

Question 11

if a forward reaction is exothermic…

Answer 11

an increase in temperature decrease the amount of products formed, and a decrease of temperature increases the amount of product formed

Question 12

if a forward reaction is endothermic…

Answer 12

a decrease in temperature decrease the amount of products formed, and an increase of temperature increases the amount of product formed

Question 13

why is ammonia important

Answer 13

because it can fertilize plants

Question 14

what are the raw materials for the productions of ammonia

Answer 14

nitrogen from and the air and hydrogen which we get from natural gas

Question 15

explain how the Haber process works

Answer 15

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

Question 16

explain how pressure can affect the production of ammonia

Answer 16

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

Question 17

what are the disadvantages of using high pressure in the ammonia reaction

Answer 17

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

Question 18

explain how temperature can affect the production of ammonia

Answer 18

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

Question 19

why is iron important to use

Answer 19

because it is considered a catalyst that would speed up both sides of the reaction meaning that ammonia is made faster

Question 20

why is sulphuric acid important

Answer 20

because it is used to make paint, pigments, fertilizers, plastics, synthetic fibers, and dye

Question 21

what are the raw materials for the contact process

Answer 21

sulfur, air, and water

Question 22

how does the contact process happen

Answer 22

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