Cracking hydrocarbons

Question 1

What is cracking?

Answer 1

Breaking down large hydrocarbon molecule chains into smaller useful ones

Question 2

What are the three steps for cracking?

Answer 2

1. Heat the hydrocarbons at a high temp

2. Mix with steam or pass over a hot catalyst

Question 3

What test can we react products with to test for saturation?

Answer 3

Bromine water test

Question 4

If the test is positive what colour does the water go?

Answer 4

Colourless

Question 5

If the test is negative what colour does the water go?

Answer 5

Orange

Question 6

Is positive alkanes or alkenes?

Answer 6

alkenes

Question 7

Cracking is an example of…?

Answer 7

Thermal decomposition

Question 8

What are plastics made from?

Answer 8

Monomers and polymers

Question 9

Explain polymerisation

Answer 9

1. Double bond opens up

2. Replaced by single bonds and lots of monomers join up

Question 10

Many polymers are not biodegradable. What does this mean?

Answer 10

They do not get broken down by microbes (problems with waste disposal)

Question 11

What two things are plastic bags made of?

Answer 11

Polymers and cornstarch

Question 12

What is the reaction for ethanol fermentation with yeast?

Answer 12

Sugar + yeast ——-> Carbon dioxide + ethanol

Question 13

What % of ethanol is made this way?

Answer 13

80%

Question 14

Give two cons about fermentation?

Answer 14

• Gives of CO2

- Takes longer to produce

Question 15

What is the reaction for a hydration reaction?

Answer 15

Ethene + steam ——> Ethanol