Crude Oil and Fuels Flashcards
What is viscosity?
How thick a substance is
What is crude oil formed of?
The remains of ancient biomass that died millions of years ago. Mainly plankton
What differentiates an alkane from an alkene?
Alkanes: have only single bonds in them.
Alkenes: have double bonds.
What is the formula for an alkane?
CnH2n + 2
How does the length of a hydrocarbon chain affect flammability?
Longer chain = lower flammability
How does the length of a hydrocarbon chain affect boiling point?
Longer chain = higher boiling point
How does the length of a hydrocarbon chain affect viscosity?
Longer chain = higher viscosity
What is the first step of fractional distillation?
Crude oil is vapourised.
What is the second step of fractional distillation?
The hydrocarbon gases enter the column.
What is the third step of fractional distillation?
The hydrocarbon gases begin to rise up the column.
What is the fourth step of fractional distillation?
As the hydrocarbon gases rise up the fractional distillation column, they cool down.
How does temperature change as you go up a fractional distillation column?
Higher up the column -> cooler
What happens when hydrocarbon gases in the fractional distillation column reach their boiling points?
They condense.
What happens when gases in the fractional distillation column condense?
They become and a fraction and are collected.
What is the temperature at the bottom of the fractional distillation column?
350°C
What is the temperature at the top of the fractional distillation column?
50°C
What is the structure of hydrocarbon molecules at the top of the fractional distillation column?
Short-chain hydrocarbons with low boiling points.
From the top to bottom, name, in order, the fractions collected from a column.
- Petroleum gas
- Petrol
- Kerosene
- Diesel oil/gas oil
- Residue (thick, sticky mixture of long-chain hydrocarbons used in making roads and flat roads)
What fuels can be produced from fractional distillation?
Petrol, diesel oil, kerosene, heavy fuel oil, petroleum gases
What is cracking?
The process of breaking up longer-chain hydrocarbons into smaller-chain ones.
What does cracking produce?
Shorter-chain alkanes and alkenes.
What two things can be used in cracking?
A zeolite catalyst, steam
Why is cracking needed?
Shorter-chain hydrocarbons tend to be more useful so are in higher demand.
What makes an alkene different from an alkane?
Alkenes have double bonds between carbons.
What is the test for an alkene?
Bromine water. If an alkene is present, it turns from orange to colourless
What effect do alkanes have on bromine water?
None.
What is a fraction?
A group of hydrocarbons with similar chain lengths.
What four useful materials can be produced from crude oil fractions?
Solvents, lubricants, polymers, detergents
What are alkenes used for?
The formation of polymers.
What is the reactivity of alkenes (compared to alkanes)?
Alkenes are much more reactive.
