Alkenes

Question 1

Alkenes have ____ carbon bonds

Answer 1

Alkenes have double carbon bonds

(ethene)

Question 2

Define ‘alkenes’

Answer 2

Hydrocarbons which have a double bond between two of the carbon atoms in their chain

Question 3

Alkenes are known as ____ because they can ____ ____ ____

Answer 3

Alkenes are known as unsaturated because they can make more bonds

Question 4

How can alkenes make more bonds?

Answer 4

The double bond can open up, allowing the two carbon atoms to bond with other atoms

Question 5

Name the first two alkenes and the amount of carbon atoms in them

Answer 5

1. Ethene (2 Cs)
2. Propene (3 Cs)

Question 6

What is the general formula for alkenes?

+ define with words

Answer 6

C_nH_2n

They have twice as many hydrogens as carbons

Question 7

Draw ethene’s structure and give its formula

Answer 7

C₂H₄

Question 8

Draw propene’s structure and give its formula

Answer 8

C₃H₆

Question 9

What is the test for alkenes?

Answer 9

Bromine water - it turns it from orange to colourless

Question 10

What do alkenes do to bromine water?

Answer 10

Decolourises it turning it from orange to colourless

Question 11

Why do alkenes turn bromine water from orange to colourless?

Answer 11

Because the double bond open up and form bonds with the bromine

Question 12

Name the affixes from 1-4 that tell you how many carbon atoms are in an alkene/alkane, and what comes after?

Answer 12

1. Meth-
2. Eth-
3. Prop-
4. But-

SHAPES (e.g. pent-, hex-, hept-)

Question 13

What is the acrostic memory thing for remembering the order of the affixes of alkenes and alkanes?

Answer 13

M y

E lephant

P oos

B lue

SHAPES