introduction to hydrocarbons

Introduction to
Hydrocarbons

Hydrocarbons

compounds that contain hydrogen and carbon

ONLY

means one or more of the bonds between carbon atoms are double bonds

Unsaturated

means the bonds between carbon atoms are only single bonds

Saturated

Saturated or Unsaturated

Unsaturated

Saturated

Saturated or Unsaturated

​single bond between the carbons double bond between the carbons

Multiple Choice

Which of these molecules is a saturated hydrocarbon ?

Saturated hydrocarbons are called alkanes.

eg. methane butane hexane

Their names all end in -ane

Alkanes

the first part of the name tells us the number of carbons in the molecule

pent = 5
hex = 6
hept = 7
oct = 8

meth = 1
eth = 2
prop = 3
but = 4

Match

match the molecule with its name.

methane

ethane

propane

butane

hexane

• methane

• ethane

• propane

• butane

• hexane

​Prop ane

​Prop tells us there are 3 carbon atoms in the molecule

​ane tells us the molecule is saturated so all the carbon to carbon bonds are single bonds

​Prop ane

Reorder

put these molecules in ascending order of the number of carbons.

• methane

• ethane

• propane

• butane

• pane

1

2

3

4

5

• 1
• 2
• 3
• 4
• 5

molecular formula

this is just the number of atoms of each element in a compound.

its molecular formula is C₅H₁₂
because it has 5 carbons and 12 hydrogens

​This is pentane. It has all single bonds and five carbons

​Note: the carbons always come first, then the hydrogens

Match

Match the molecular formula with the structure of these hydrocarbons

C₃H₆

C₄H₁₀

C₄H₈

C₈H₁₈

C₅H₁₂

• C₃H₆

• C₄H₁₀

• C₄H₈

• C₈H₁₈

• C₅H₁₂

Multiple Choice

Which of these molecules is butane ?

Different types of formula - 1

displayed formula
shows the positions of all the atoms and bonds in a molecule

C₃H₈
Propane

molecular formula
shows the number of atoms of each element in the compound