Using Resources Haber Stuff Continued (Unit 10)

Question 1

What is the Haber Process?

Answer 1

Process of making ammonia

Question 2

What is the word formula for the Haber process?

Answer 2

Nitrogen + Hydrogen ⇌ Ammonia

Question 3

What is the symbol equation for the Haber process? Give state symbols and exo/endo direction

Answer 3

N2(g) + 3H2(g) ⇌ 2NH3 (g)

Forward is exothermic, backward is endothermic

Question 4

Where do you get the reactant gases from?

Answer 4

Nitrogen from the air

Hydrogen from methane

Question 5

What is ammonia useful for?

Answer 5

Ammonia-based fertilisers

Question 6

How is ammonia made in industry?

Answer 6

1) gases are heated and vaporised and put through a COMPRESSOR with the conditions mentioned
2) Gaseous mixture is put through a REACTION CHAMBER with the catalyst
3) The gaseous mixture passes through a condenser. Only ammonia condenses as it condenses at highest temperature
4) Liquid ammonia is REMOVED (do you know why?)
5) The unreacted nitrogen and hydrogen is recycled

Question 7

What are the conditions used in the industry making of Haber process? say in general terms too

Answer 7

200 atm (NOT atmospheric pressure)
450°C
Iron catalyst
High pressure, MEDIUM temperature

Question 8

Which side has more moles in the Haber process?

Answer 8

Reactant as has 4 moles (remember to add moles)

Question 9

Why is there high pressure used?

Answer 9

1) increases RATE OF REACTION because more particles per unit volume of gas, so more freq. succ. conditions
2) increased YIELD as equilibrium shifts to the right to decrease pressure (favours side with less moles). More product and less reactant so more yield

Question 10

Why is the increase in temperature used?

Answer 10

Higher rate of reaction is more important than yield as overall more product is formed quicker

2) increases RATE OF REACTION as particles have more KE so more freq. succ. collisions
3) decrease yield as endothermic reaction favoured therefore less product made so less YIELD

Question 11

How does the recycling of the reactant gases and the REMOVAL of the liquid ammonia affect yield and rate?

Answer 11

Increases YIELD
For the removing ammonia, it shifts equilibrium to right to negate for loss of ammonia
No effect on RATE

Question 12

What compromise has been made for the temperature chosen in the industrial Haber process?

Answer 12

Compromise between yield and rate of reaction

Question 13

What are NPK fertilisers?

Answer 13

Nitrate, phosphate, potassium

Question 14

Why are these fertilisers needed?

Answer 14

The mineral ions from plants aren’t restored into the soil as the plants are harvested by farmers.

Question 15

Why are the minerals in the form of ions?

Answer 15

They become soluble which allows plants to absorb them

Question 16

How are these ions made?

Answer 16

By reacting with ammonia!

Question 17

What is the formula for phosphoric acid?

Answer 17

H3PO4

Question 18

What is the formula for nitric acid?

Answer 18

HNO3

Question 19

The ions come in the form of SALTS. What are the word equations for making these ammonium salts?

Answer 19

Ammonia + nitric acid —> ammonium nitrate

Ammonia + phosphoric acid —> ammonium phosphate

Ammonia + sulfuric acid —> ammonium sulfate

Question 20

Why aren’t ammonium salts made with potassium?

Answer 20

All potassium salts are soluble anyway e.g. potassium chloride, potassium sulfate

Question 21

What is the formula for ammonium nitrate?

Answer 21

NH3NO4

Question 22

What is the formula for ammonium phosphate?

Answer 22

(NH4)3 PO4

Question 23

What is the formula for ammonium sulfate?

Answer 23

(NH4)2 SO4

Question 24

What type of reaction is making the ammonium salts?

Answer 24

Neutralisation reaction

Question 25

Is ammonia a base, acid, or an alkali?

Answer 25

Alkali

Question 26

What is the definition of a salt?

Answer 26

A metal OR ammonia reacting with an acid (since ammonia is alkali)

Question 27

If this is a neutralisation reaction for making ammonium salts, why isn’t water produced?

Answer 27

The Hydrogen is used in making the NH3 to NH4 because ammonia AS AN ION is NH4+

Question 28

What type of nutrients are NPK?

Answer 28

Macronutrients

Question 29

What are the mineral ions in NPK useful for in plants?

Answer 29

NitrATE ions are for green foliage PhosphATE ions make roots strong Potassium ions are for healthy growth

Question 30

There is an issue here that we can make the phosphate fertilisers only from reacting stuff with phosphate rock. Where do we get it from?

Answer 30

From MINING

Question 31

Why can’t we just use phosphate rock for the plants?

Answer 31

It is INSOLUBLE

Question 32

How do we get the ammonium phosphate salts?

Answer 32

1) phosphoric rock + nitrate acid —> phosphoric acid | Phosphoric acid + ammonia —> ammonium phosphate

Question 33

Alternatively we can make phosphate fertilisers. How do we do this?

Answer 33

Phosphate rock + sulfuric acid —> single superphosphate Phosphate rock + phosphoric acid —> triple superphosphate

Question 34

What is single superphosphate made up of?

Answer 34

Calcium phosphate and calcium sulfate

Question 35

What is triple phosphate made up of?

Answer 35

Calcium phosphate

Question 36

How does catalyst affect rate and yield?

Answer 36

Increases RATE, no effect YIELD

Question 37

Is the Haber process the general name for making ammonia or is it the name for the industrial process?

Answer 37

It’s he name for the industrial process

Question 38

Define fertiliser

Answer 38

Chemical or natural substance added to soil or land to improve growth of plants

Question 39

How do you make fertilisers in the lab?

Answer 39

Ammonia + sulfuric acid —> ammonia sulfate 1) Add 25cm ³ of ammonia to a conical flask 2) Fill a burette with sulfuric acid to the brim where it says 0 3) Open the tap to add acid to the flask, swirling regularly 4) using a glass rod, test the drop of the solution with litmus paper or phenolphthalein indicator until you see a colour change (neutralisation) N.B do this out the flask so don’t contaminate solution 5) record final burette reading 6) Heat solution to get crystals

Question 40

Compare lab process of making fertiliser vs industrial process.

Answer 40

Lab is SMALL scale (e.g. 25cm³) - industrial is LARGE SCALE (tonnes) Lab is safe as dilute acid/alkali concentrations are used - risk if EXPLOSION in industry AND dangerous chemicals used/concentrated Lab uses glass pipette and burette - industry uses stainless steel pipes and vessels Lab reaction is at room temperature - industry has high temperature AND pressure Lab process uses titration and crystallisation - industry sprays conc. sulfuric acid into ammonia gas

Question 41

In terms of commercially used conditions for specific RAW MATERIALS and ENERGY SUPPLIES, how and why has industry adapted to these factors?

Answer 41

Hydrogen and ammonia is recycled as it is expensive to extract/finite Also this leads into energy CONSUMPTION and therefore COST