post it

Post itPollutants are dangerous chemicals in the air are called pollutants.

Name as many air pollutants as you can from last lesson.

Extension: Circle those which could lead to acid rain

Hydrocarbons and fossil fuels

To develop an understanding of how air pollutants are produced

Grade criteria Grade A* - Generate combustion reactions using balance symbol equations. Grade A – Summarise combustion reactions using word equations. Grade B – Explain how atoms are conserved during combustion reactions. Grade C – Identify hydrocarbons and fossil fuels by their molecular pictures Grade D –Define the terms ‘hydrocarbon’ and ‘fossil fuels’, giving examples of each

When a substance burns, it is said to combust.

A fuel is a substance that reacts with oxygen (combusts) to release useful energy.

Combustion, fuels and hydrocarbons

Many fractions obtained from crude oil are used as fuels because they contain hydrocarbons that burn easily and release a large amount of useful energy.

Combustion is a rapid reaction between a substance and oxygen that releases heat and light energy.

Hydrocarbons – What’s so good about them?

• Contain carbon and hydrogen atoms only• Can have different carbon chain lengths• Length of the chain determines the use• Crude oil is a mixture of lots and lots of

different hydrocarbons.

What are the products of thecomplete combustion of a hydrocarbon?

Plenty of air is needed to provide enough oxygen for a hydrocarbon fuel to burn completely.

oxygen carbon dioxidehydrocarbon + + water

The blue flame of a gas hob or a Bunsen burner is an example of complete combustion of a hydrocarbon (in this case, natural gas).

Complete combustion of hydrocarbons

Do you think that combustion is as simple as:

oxygen carbon dioxidehydrocarbon + + water

VCOP – What are particulates?

Consider your observations, which flame would it have been?

Grade criteria Grade A* - Generate combustion reactions using balance symbol equations. Grade A – Summarise combustion reactions using word equations. Grade B – Explain how atoms are conserved during combustion reactions. Grade C – Identify hydrocarbons and fossil fuels by their molecular pictures Grade D –Define the terms ‘hydrocarbon’ and ‘fossil fuels’, giving examples of each

Plenary: Methane bubbles

• What is a hydrocarbon? Name an example

• Give a general word equation for combustion

• Name a product of incomplete combustion? How is it harmful?

• Balance the equation

Homework

• Complete pages 20 – 23/24/25

For each answer below write as many questions as you can think of

I am the answer.... So I am the Question

Hydrocarbon

Acid rain

Nitrogen Monoxide

Combustion

Carbon Dioxide + Water

Crude oil

Explain why crude oil is an invaluable resource

• Know the origins of crude oil• Describe the process to separate

crude oil• Recognise the uses of the fractions of

crude oil

What genre of chemicals do you get?

Hydrocarbons – What’s so good about them?

• Contain carbon and hydrogen atoms only• Can have different carbon chain lengths• Length of the chain determines the use• Crude oil is a mixture of lots and lots of

different hydrocarbons.

Crude Oil

• Microscopic plants and animals die and fall to the sea bed• Layers of sand and mud form on top• Pressure and high temperature cause oil to form

How crude oil was formed

• Oil obtained by drilling

Explain why crude oil is an invaluable resource

• Know the origins of crude oil• Describe the process to separate

crude oil• Recognise the uses of the fractions of

crude oil

Heated Crude Oil

350o

C

40o

C

Fraction Boiling pt.

< 25oC

25 – 60oC

60 – 180oC

180 – 220oC

220 – 250oC

250 – 300oC

300 – 350oC

> 350oC

Average number of C atoms in chain

3

8

10

12

20

40

80

120

The Fractional Distillation of Crude Oil

Refinery gas

Petrol

Naptha

Kerosine

Diesel oil

Fuel oil

Lubricating oil

Bitumen

Explain why crude oil is an invaluable resource

• Know the origins of crude oil• Describe the process to separate

crude oil• Recognise the uses of the fractions of

crude oil

The Molymod challenge

• Rules Carbon atoms always make 4 bonds• Hydrogen atoms are smaller• Hydrogen atoms can only make one bond

Make the molecule methane (1 Carbon to 4 Hydrogens) Make the molecule propane (3 carbons to ? Hydrogens)Make the molecule hexane (? Carbons to 14 Hydrogens)

Match the hydrocarbon to its properties

Match the hydrocarbon to its properties

carbon monoxide

carbon dioxide

sulfur dioxide

nitrogen monoxide

nitrogen dioxide

water (hydrogen oxide)

formula CO SO2

carbon atoms

1

sulfur atoms

nitrogen atoms

hydrogen atoms

oxygen atoms

1

Complete the table

Extension: what is the word equation for combustion?