Fertilisers and chemicals

Question 1

what do fertilisers provide?

Answer 1

mineral ions needed for healthy growth in plants

Question 2

why do farmers need to constantly replenish their soil with fertiliser? (2)

Answer 2

-as plants grow, they absorb mineral ions from the water in the soil (through their root hair cells)
-overtime, the concentration of these ions decreases, so farmers and gardeners add fertilisers to the soil.

Question 3

what do fertilisers contain? for what reason?
what are these often referred to as?

Answer 3

nitrogen, phosphorus and potassium compounds to promote plant growth
NPK fertilisers

Question 4

what must fertiliser compounds be? or what reason?

Answer 4

soluble in water so they can be absorbed by the root hair cells:

Question 5

what are sources of nitrogen, phosphorus and potassium? (3)

Answer 5

nitrogen: ammonium ions, NH4+, and nitrate ions, NO3-
phosphorus: phosphate ions, PO43-
all common potassium compounds dissolve in water to produce potassium ions, K+

Question 6

what is the symbol equation for ammonium nitrate?

Answer 6

NH4NO3

Question 7

what is the equation (word and symbol) for the production of ammonium nitrate?

Answer 7

Ammonia + nitric acid → ammonium nitrate

NH3(aq) + HNO3(aq) → NH4NO3(aq)

Question 8

what are ammonium nitrate ammonium sulphate sources of and what can it be used as?

Answer 8

soluble nitrogen, so it can be used as a ‘nitrogenous’ fertiliser.

Question 9

what is ammonia manufactured using?
what does this involve?

Answer 9

haber process.
nitrogen and hydrogen:

Question 10

what is the symbol and word equation of the ammonia manufacturing process?

Answer 10

Nitrogen + hydrogen ⇌ ammonia

N2(g) + 3H2(g) ⇌ 2NH3(g)

Question 11

which conditions are needed for the Haber process? (3)

Answer 11

a temperature of 450°C
a pressure of 200 atmospheres
an iron catalyst

Question 12

what is the symbol and word equation of the nitric acid manufacturing process?

Answer 12

Ammonia + oxygen → nitric acid + water

NH3(g) + 2O2(g) → HNO3(aq) + H2O(l)

Question 13

how could ammonium sulfate be produced in the lab?

Answer 13

using dilute ammonia solution and dilute sulfuric acid:

Question 14

what is the word and symbol equation for the ammonium sulfate manufacturing process?

Answer 14

Ammonia + sulfuric acid → ammonium sulfate

2NH3(aq) + H2SO4(aq) → (NH4)2SO4(aq)

Question 15

what are both reactants (soluble or insoluble) and which method must be used because of this?

Answer 15

Both reactants are soluble, so a titration must be used.

Question 16

what is the main difference between a lab preparation and the industrial production of ammonium sulfate? (2)
-think of scale

Answer 16

lab preparation = small scale
industrial production = larger scale in several stages.

Question 17

where do the reactants come from during the production of ammonium sulphate for
-fertiliser factories
-laboratories

Answer 17

fertiliser factory = raw materials needed, several steps are involved
labs = two reactants are bought from elsewhere

Question 18

what is the difference between the lap preparation and industrial production of ammonium sulfate in terms of size and speed?

Answer 18

-lab preparation =
‘batch’ process.
-small amount of product is made slowly at any one time,
-apparatus cleaned ready to make another batch.
-industrial production =
- ‘continuous’ process.
-product is made quickly all the time, as long as raw materials are provided.