C10: THE HABER PROCESS + FERTILISERS

Question 1

What is ammonia used to make?

Answer 1

fertilisers

Question 2

What is ammonia made from? (+where do the elements come from?)

Answer 2

-nitrogen (from atmosphere)
-hydrogen (from natural gas)

Question 3

What is the name of the process whereby ammonia is made?

Answer 3

the Haber process

Question 4

What is the equation for the reaction to produce ammonia?

Answer 4

N2 + 3H2 ⇌ 2NH3

Question 5

What is the Haber process?

Answer 5

-nitrogen extracted from air and hydrogen from natural gas are pumped through pipes
-the pressure of the mixture of gases is increased to 200 atm
-the pressurised gases are heated to 450°C and passed through a tank containing an iron catalyst
-the reaction mixture is cooled so that ammonia liquefies and can be removed (unreacted nitrogen and hydrogen are recycled)

Question 6

What are the conditions required for the Haber process?

Answer 6

-iron catalyst
-temp of ~450°C
-high pressure of 200 atm

Question 7

Why is an iron catalyst used?

Answer 7

-increases rate of reaction by lowering activation energy
-no effect on yield

Question 8

Why is a temp of ~450°C used?

Answer 8

-increases rate of reaction (more kinetic energy so more frequent and more successful collisions)
-high temp decreases yield so a compromise temp of ~450°C is used (high enough for fast rate, not too high that yield is low)

Question 9

Why is a pressure of 200 atm used?

Answer 9

-increases rate of reaction (more frequent collisions)
-increases yield

Question 10

What are fertilisers?

Answer 10

formulations of various salts that provide mineral ions needed for healthy growth in plants

Question 11

What are NPK fertilisers?

Answer 11

fertilisers containing nitrogen (N) , phosphorus (P) and potassium (K)

Question 12

Where does the nitrogen used in NPK fertilisers come from?

Answer 12

from ammonia in Haber process

Question 13

Where does the phosphorous used in NPK fertilisers come from?

Answer 13

from phosphate rock

Question 14

Where does the potassium used in NPK fertilisers come from?

Answer 14

from mining KCl and K2SO4

Question 15

What salts are manufactured from ammonia and how?

Answer 15

-ammonium phosphate ((NH4)2PO4) (made by reacting ammonia with phosphoric acid)
-ammonium sulfate ((NH4)2SO4) (made by reacting ammonia with sulfuric acid)
-ammonium nitrate (NH4NO3) (made by converting ammonia into nitruc acid then reacting ammonia with the nitric acid)

Question 16

What salts are manufactured from phosphate rock and how?

Answer 16

-single superphosphate (made by reacting phosphate rock with sulfuric acid)
-triple superphosphate (made by reacting phosphate rock with nitric acid to make phosphoric acid and then reacting the phosphoric acid with phosphate rock)
-ammonium phosphate (made by reacting phosphate rock with nitric acid to make phosphoric acid and then reacting the phosphoric acid with ammonia)

Question 17

What salts are mined?

Answer 17

-potassium chloride (KCl)
-potassium sulfate (K2SO4)