fertilisers

Question 1

what elements are essential for plant growth?

Answer 1

• nitrogen
• phosphorus
• potassium

Question 2

why are fertilisers used by farmers?

Answer 2

to restore essential nutrients to the soil

Question 3

what must fertilisers be?

Answer 3

soluble in water

Question 4

how is ammonia produced?

Answer 4

haber process

Question 5

what temperature is the haber process carried out at?

Answer 5

400-450 degrees

Question 6

what pressure is the haber process carried out at?

Answer 6

200atm

Question 7

what catalyst is used during the haber process?

Answer 7

iron catalyst

Question 8

what are the unreacted gases in the haber process?

Answer 8

• nitrogen
• hydrogen

Question 9

what happens to the unreacted gases in the haber process?

Answer 9

they are recycled

Question 10

what is the reaction between nitrogen and hydrogen to make ammonia?

Answer 10

exothermic

Question 11

is the haber process reaction reversible?

Answer 11

yes

Question 12

why is the iron catalyst in the form of pellets?

Answer 12

to maximise the surface area available

Question 13

what happens if the temperature is too low during the haber process?

Answer 13

the reaction rate is too slow to be economical

Question 14

why is ammonium nitrate an effective fertiliser?

Answer 14

• contains nitrogen
• very soluble

Question 15

what is the product of the ostwald process?

Answer 15

nitric acid

Question 16

what are the reactants of the ostwald process?

Answer 16

• ammonia
• oxygen
• water

Question 17

what is the catalyst used in the ostwald process?

Answer 17

platinum