What property allows chemists to separate gasoline from asphalt and paint thinner from jet fuel?

1 Answer
Aug 4, 2017

Answer:

#"Differential volatility............"#

Explanation:

The crude oil that is pumped from the ground is a mixture of hydrocarbons: small and simple ones such as methane and ethane, and progressively longer chain hydrocarbons all the way up to tars and bitumen, which are usually polycyclic benzene derivatives that are highly involatile.....and of course very, very sticky and tacky.

Of course when they tap an oil well, and remove its contents for processing, the crude oil is distilled at an oil refinery on a fractionating tower that may be many metres tall. The length of the tower allows efficient separation (so-called #"fractionation"#) of the crude petroleum into so-called distillates; i.e. they collect the fractions boiling between #40-60# #""^@C#, #60-80# #""^@C#, #90-110# #""^@C#, and these fractions are a mixture of alkanes and olefins; the longer the chain the more involatile the material.