Alkenes and Ethanol

Question 1

Alkenes have a…

Answer 1

C=C double bond.

Question 2

Why are alkenes known as unsaturated?

Answer 2

Because they can make more bonds. (the double bonds can open up, allowing the two carbon atoms to bond with other atoms)

Question 3

What are the first two alkenes and what are their formulas?

Answer 3

Ethene - C2H4

Propene - C3H6

Question 4

How do you test for an alkene?

Answer 4

Use bromine water. An alkene, when mixed with bromine water will decolourise it.

Question 5

What are the two ways in which ethanol can be made?

Answer 5

Reacting ethene with steam and fermentation.

Question 6

What is the equation for the fermentation of ethanol?

Answer 6

sugar>carbon dioxide+ethanol

Question 7

What is an advantage and disadvantage of making ethanol by fermentation?

Answer 7

Advantages: Process only requires a low temperature and simple equipment, renewable source, reasonably cheap
Disadvantages: Isn’t very concentrated, has to be distilled to concentrate it, has to be purified.