Most of the topic

Question 1

What is sacrificial protection?

Answer 1

When a coating of another more reactive metal is applied, so the coating reacts with the oxygen instead of the actual metal

Question 2

What is bronze an alloy of?

Answer 2

Copper and tin

Question 3

What is brass an alloy of?

Answer 3

copper and zinc

Question 4

What is soda-lime glass made of?

Answer 4

Sand, sodium carbonate, limestone

Question 5

What is borosilicate glass made of?

Answer 5

sand, boron trioxide

Question 6

What is the difference between borosilicate glass and soda lime glass?

Answer 6

Borosilicate melts at higher temperatures

Question 7

How is clay made?

Answer 7

Wet clay is shaped and heated in a furnace

Question 8

What is the structure of glass?

Answer 8

Irregular giant lattice

Question 9

What are composites made from?

Answer 9

Two materials, a matrix or binder surrounding the reinforcement (the actual material)

Question 10

Difference between the physical characteristics and structure of LD and HD polymer?

Answer 10

LD - Softer (less compact)

HD - Harder (more compact)

Question 11

Conditions for making LD polymer?

Answer 11

Low temperature
Low pressure
Different catalyst

Question 12

Conditions for making HD polymer?

Answer 12

Moderate temperature
Higher pressure
Catalyst

Question 13

Describe the structure of thermosetting and thermosoftening polymer?

Answer 13

Thermosetting
Strong covalent bonds between polymer molecules, very strong

Thermosoftening
Weak intermolecular forces between the chains and heating breaks the forces

Question 14

What is the haber process used for?

Answer 14

Producing ammonia which can be used in NPK fertiliser

Question 15

What are the raw materials for the haber process and where do they come from?

Answer 15

Nitrogen (from air) and hydrogen (from natural gas)

Question 16

Explain the haber process?

Answer 16

Nitrogen and hydrogen are passed over a iron catalyst at a high temperature of 450°C and a high pressure of 200 atm. Some of the hydrogen and nitrogen reacts to form ammonia. The reaction is reversible so some of the ammonia produced breaks down into nitrogen and hydrogen. The ammonia enters a cooling chamber, the ammonia liquefies and is removed. The remaining hydrogen and nitrogen are recycled.

Question 17

Why is the ammonia removed from the haber process?

Answer 17

To provoke the reaction (le chateliers principle)

Question 18

What is ammonia used to manufacture?

Answer 18

Ammonium salts and nitric acid

Question 19

What is NPK fertiliser?

Answer 19

A formulation of ions of nitrogen, phosphorus and potassium

Question 20

Compare the production of fertiliser in industry vs a lab?

Answer 20

Lab - dilute ammonia and nitric acid
Industry - Concentrated nitric acid, ammonia gas (exothermic reaction)
Lab - water bath with bunsen burner
Industry - Heated using the exothermic reaction (earlier)
Lab - Batch process
Industry - Continuous process

Question 21

Is the haber process endothermic or exothermic?

Answer 21

Exothermic

Question 22

Why is 200 atm used in the haber process? Why not higher?

Answer 22

Le chatelier’s principle. If you increase the pressure then the equilibrium will shift towards the side with the least number of gas molecules. In the haber process, the forward reaction has the least number of gas molecules so the pressure is increase so that more product is formed. The pressure isn’t above 200 atm because then it would be dangerous and expensive

Question 23

Why is 450 degrees used, why not higher?

Answer 23

Le chatelier’s principle says if you increase the temperature then the products will decrease for an exothermic reaction so there would be less ammonia, so the temperature should be as low as possible, however if the temperature was too low then the rate of reaction and collisions would also be low, so 450 degrees is a used as a compromise between yield and rate