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nat 5 chemistry > Fertilisers > Flashcards

Flashcards in Fertilisers Deck (15)
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1
Q

What must fertilisers be ?

A

Soluble and contain at least one of the 3 essential elements for plant growth (NPK)

2
Q

What are NPK essential for ?

A

Plant growth

3
Q

What is the haber process involved in ?

A

Production of fertilisers

4
Q

What is the haber process an example of ?

A

Reversible reaction

5
Q

What is the equation for the haber process ?

A

N2 + 3H2🔄2NH3

6
Q

What are the 2 raw materials in the haber process

A

Nitrogen from air

Hydrogen from natural gas

7
Q

What happens to unreacted N2 and H2 ?

A

Recycled

8
Q

What is the Ostwald process ?

A

Industrial method of making nitric acid from ammonia. Nitric acid is then used to make nitrate fertilisers.

9
Q

What are the 3 stages of the Ostwald process ?

A

Oxygen added to ammonia to produce nitrogen monoxide
Then nitrogen dioxide
Then dissolved in water to make nitric acid

10
Q

What are the reaction conditions in the Ostwald process

A
  1. High temperature (800c)

2. Platinum catalyst

11
Q

What happens to the platinum catalyst in the Ostwald process ?

A

Is heated but continues to glow when the heat is removed because the oxidation of ammonia is exothermic

12
Q

What is the equation for percentage composition ?

A

%mass=

    mass of element ➗
    GFM of compound         ✖️100
13
Q

What can some salts produced from neutralisation be used as ?

A

Fertilisers

14
Q

What are the 3 essential elements for plant growth ?

A

Nitrogen
Phosphorus
Potassium

15
Q

What catalyst is used in the haber process ?

A

Iron