Alkanes and Alkenes Worksheet How can we distinguish between alkanes and alkenes?
Aim: To work out the best way to distinguish alkanes from alkenes.
1
Given below are the structures of four hydrocarbons:
A
B
C
D
Explain why all four compounds above are hydrocarbons.
..........................................................................................................................................................
..........................................................................................................................................................
2
Classify the compounds A to D as either alkanes or alkenes.
Compound
Molecular formula
A
B
C
D
3
The general formula for alkanes is CnH2n+2.
What is the general formula for alkenes? ……………………….
4
Classify the following compounds as either alkanes or alkenes:
E
C3 H8
alkane/alkene
F
C5H10
alkane/alkene
G
C6H14
alkane/alkene
H
C6H12
alkane/alkene
I
C5H12
alkane/alkene
Alkane or alkene?
5
Distinguishing between alkanes and alkenes using chemical reactions:
Test
alkane
alkene
Combustion
Bromine water
6
Which of these tests is the better one?
Explain your answer. .......................................................................................................................
7
Complete the following true/false statements about alkenes.
a)
All alkenes are hydrocarbons.
true/false
Reason ....................................................................................................................................
.................................................................................................................................................
b)
Their general formula is CnH2n+2.
true/false
Reason ....................................................................................................................................
.................................................................................................................................................
c)
Ethene is an alkene.
true/false
Reason ....................................................................................................................................
d)
Alkenes decolourise bromine water.
true/false
Reason ....................................................................................................................................
e)
C4H10 is an alkene.
true/false
Reason ....................................................................................................................................
f)
Alkenes burn with a non-smoky flame.
true/false
Reason ....................................................................................................................................
.................................................................................................................................................
g)
The formula C4H8 represents an alkene.
true/false
Reason ....................................................................................................................................
.................................................................................................................................................