Chemistry IGCSE Oxford AQA organic
chemistry Exam study guide COMPLETE
EXAM Questions and Answers (Verified
Answers) (Latest Update 2026)
Crude oil is a mixture of... -CORRECTANSWER A very large number of compounds
Most of the compounds in crude oil are... -CORRECTANSWER hydrocarbons
What are hydrocarbons? -CORRECTANSWER Molecules made up of hydrogen and
carbon atoms only
How are the many kinds of hydrocarbons separated? -CORRECTANSWER They are
separated into fractions, each of which contains molecules with a similar number of
carbon atoms
Describe the process of fractional distillation -CORRECTANSWER >The crude oil is
heated so that it
>vaporizes the hydrocarbons
and inserted into the fractioning column.
>Next, there is a temperature gradient, where highest boiling points are found at the
bottom
>hydrocarbons condense at different levels in the column
, Most of the hydrocarbons in crude oil are (what kind of hyrdocarbon) -
CORRECTANSWER saturated. They are called alkanes
What is the general formula for alkanes -CORRECTANSWER CnH2n+2
What kind of bonds are found in an alkane -CORRECTANSWER all the carbon-carbon
bonds are single covalent bonds
Displayed formula and normal formula of ethane -CORRECTANSWER C2H6
What are the first three kinds of alkanes -CORRECTANSWER methane, ethane and
propane
The properties of hydrocarbons depend on -CORRECTANSWER the size of the
molecule
State the relationship between boiling point, viscosity, flammability and the size of the
hydrocarbon -CORRECTANSWER As the size of the molecule increases,
Flammability decreases
Viscosity increases
Boiling point increases
chemistry Exam study guide COMPLETE
EXAM Questions and Answers (Verified
Answers) (Latest Update 2026)
Crude oil is a mixture of... -CORRECTANSWER A very large number of compounds
Most of the compounds in crude oil are... -CORRECTANSWER hydrocarbons
What are hydrocarbons? -CORRECTANSWER Molecules made up of hydrogen and
carbon atoms only
How are the many kinds of hydrocarbons separated? -CORRECTANSWER They are
separated into fractions, each of which contains molecules with a similar number of
carbon atoms
Describe the process of fractional distillation -CORRECTANSWER >The crude oil is
heated so that it
>vaporizes the hydrocarbons
and inserted into the fractioning column.
>Next, there is a temperature gradient, where highest boiling points are found at the
bottom
>hydrocarbons condense at different levels in the column
, Most of the hydrocarbons in crude oil are (what kind of hyrdocarbon) -
CORRECTANSWER saturated. They are called alkanes
What is the general formula for alkanes -CORRECTANSWER CnH2n+2
What kind of bonds are found in an alkane -CORRECTANSWER all the carbon-carbon
bonds are single covalent bonds
Displayed formula and normal formula of ethane -CORRECTANSWER C2H6
What are the first three kinds of alkanes -CORRECTANSWER methane, ethane and
propane
The properties of hydrocarbons depend on -CORRECTANSWER the size of the
molecule
State the relationship between boiling point, viscosity, flammability and the size of the
hydrocarbon -CORRECTANSWER As the size of the molecule increases,
Flammability decreases
Viscosity increases
Boiling point increases
