C6.1 Improving Processes and Products

Question 1

What method is used to extract iron from iron oxide?

Answer 1

Reduction of iron oxide with carbon

Question 2

Name two products of copper oxide being heated with charcoal (carbon).

Answer 2

Copper and carbon dioxide

Question 3

Describe how electrolysis is used to extract a metal from its ore.

Answer 3

• metal containing compound is melted, and an electric current is passed through it
• pure metal discharges at the cathode
• non metal (usually oxygen) discharged at the anode

Question 4

Describe what biobleaching is.

Answer 4

• the process of using bacteria to separate metal ions from their ores
• the solution produced (leachate) contains metal ions, which can be extracted by displacement or electrolysis

Question 5

Describe the process of phytoextraction.

Answer 5

• growing plants in soil containing metal compounds
• plants absorb the metal compounds
• plants then harvested, dried and burned in a furnace
• ash contains soluble metal compounds from which the metal can be extracted by displacement or electrolysis

Question 6

Why is biological extraction encouraged?

Answer 6

• less harm to the environment compare to traditional mining methods
• there is a limited supply of metal ores
• demand for metals is growing

Question 7

Bronze is an alloy of which two metals?

Answer 7

Copper and tin

Question 8

What alloy is formed from copper and zinc?

Answer 8

Brass

Question 9

What is corrosion?

Answer 9

The process by which something is slowly damaged or destroyed by a chemical process.

Question 10

What is the primary use of ammonia?

Answer 10

Fertilisers

Question 11

What is the main source of ammonia production?

Answer 11

The Haber Process

Question 12

Temperature used for Haber process:

Answer 12

450 degrees Celsius

Question 13

Reactants in production of ammonium nitrate:

Answer 13

Ammonia and nitric acid

Question 14

How to make ammonium sulfate:

Answer 14

• place dilute ammonia solution NH3 (aq) in a conical flask with methyl orange indicator
• add dilute sulfuric acid, H2SO4 (aq), from a burette or dropping pipette and stop when the indicator changes from yellow to red
• once end point is achieved, add a little more ammonia solution to ensure reaction is complete

Question 15

Things to be careful for when making ammonia sulfate:

Answer 15

Ammonia solution releases small amounts of ammonia in the gas state, which has an irritating sharp smell, so you need to take care to avoid breathing it in

Question 16

Stage 1 of the contact process

Answer 16

Burning sulfur

sulfur + oxygen -> sulfur dioxide

Question 17

Stage 2 of contact process

Answer 17

Burn sulfur dioxide in air

sulfur dioxide + air -> sulfur trioxide

Question 18

Stage 3 of contact process

Answer 18

Add water to sulfur trioxide

sulfur trioxide + water -> sulfuric acid

Question 19

Sulfuric acid formula

Answer 19

H2SO4