The Alkanes

The general formula CnH2n+2

Methane (CH4) 

 Ethane (C2H6)

Propane (C3H8)

Butane (C4H10)

Pentane (C5H12)

3.4 I can recall the products of complete and incomplete combustion of alkanes

·         Saturated hydrocarbons are called alkanes

·         Small chain hydrocarbons are used as fuels

3.       The reaction is called combustion

4.       The word equation for  this chemical reaction is :

fuel (methane) + oxygen → carbon dioxide + water + ENERGY (heat, light, sound)

5.       If there is insufficient oxygen then the word equation is:

fuel (methane) + __________ → ___________ + ____________ + ENERGY (heat, light, sound)

6.       The problem with this reaction is that carbon monoxide is produced this gas is a poisonous gas to the human body (see objective 5.11)

7.       Where can you find incomplete combustion? Often in cars 

8.       What is used to reduce the harmful products from incomplete combustion? 

9.       During incomplete combustion a smoky flame is often seen, explain this observation

10.   Describe the two chemical tests for water 

- cobalt (II) chloride paper (turns from blue to pink)

- anhydrous copper (II) sulphate (turns from white to blue)

11.   Describe the chemical test for carbon dioxide gas

12.   Describe a physical test for water