C3-10 Homologous Series & Alkanes

Which of these is NOT true for a homologous series?

• They all share the same general formula

• They all have the same functional group

• They have identical chemical properties

• They differ from subsequent members by CH2

Answer explanation

They have similar chemical properties but NOT identical

The properties of an homologous series change as the carbon chain gets longer.

Use the words shorter or longer to complete the sentence:-

As the length of the chain gets ... the compounds are more viscous.

(a)  

The properties of an homologous series change as the carbon chain gets longer.

Use the words shorter or longer to complete the sentence:-

As the length of the chain gets ... the compounds are more flammable.

(a)  

The majority of the fractions from crude oil are used as:-

• Fuels

• Oils

• Gases

• Chemicals

Which two of the following describes all of the alkanes?

• Carbohydrates

• Saturated

• Hydrocarbons

• Viscsous

What is the general formula for ALL alkanes?

(a)  

Alkanes undergo complete combustion.

What will be the products?

• Carbon dioxide

• Carbon monoxide

• Water

• Hydrogen

Alkanes undergo complete combustion.

What happens to both the carbon and hydrogen atoms in the reaction?

• The activation energy is high

• This is an exothermic reaction

• They are both oxidised

• Energy is released during complete combustion

Hydrocarbon release lots of energy when they burn. Which reaction pathway shows this?

• 
• 

Which sequences are correct for the three alkanes shown?

• Methane is more flammable than propane

• Propane is more viscous than ethane

• Ethane is less volatile than methane

• Propane has a shorter chain than ethen