C7 Flashcards
(55 cards)
What is crude oil?
A finite resource found in rocks.
How was crude oil made?
Over millions of years and lots of pressure; it is buried plankton which is drilled up now.
What is crude oil mainly made up of?
Hydrocarbons: mainly alkanes.
What is a hydrocarbon?
A compound made of hydrogen and carbon atoms
What is the formula for alkanes?
CnH2n+2
What are the first 4 alkanes?
Methane. Ethane. Propane. Butane.
Where might the fractions from fractional distillation be used?
To produce fuels and feedstock for the petrochemical industry.
What are some examples of fuels which are made from crude oil?
Petrol; diesel; kerosene; heavy fuel oil and liquified petroleum gases.
What are some examples of things that are produced by the petrochemical industry?
Solvents; lubricants; polymers and detergents.
How does fractional distillation work? (4)
- The crude oil is heated and it evaporates. 2. It travels up the fractionating column - the bottom is the hottest and the top is the coolest. 3. The different fractions condense at different points due to their different boiling points. 4. Each faction is now separated :) and ready for use.
How does boiling point; viscosity; flammability and size change for hydrocarbons?
The smaller the hydrocarbon: less viscous (more runny); more flammable and a lower boiling point (more volatile). The bigger: more viscous; less flammable and a higher boiling point.
What is the equation for the complete combustion of hydrocarbons?
Hydrogen + oxygen –> water + carbon dioxide ( + energy)
What does cracking do?
Breaks long chain hydrocarbons into shorter and more useful hydrocarbons.
What are the 2 types of cracking?
Steam - needs a high temperature and catalytic - needs a high temperature and a catalyst.
What are the products of cracking?
Alkanes and some alkenes.
What is the test for alkenes?
Add bromine water —> colourless
What is distinctive about alkenes?
Double bond with carbon
What’s the equation for alkenes and what does that make them?
Cn H2n - unsaturated.
What are the first 4 alkenes?
Ethene, propene, butene, pentene
What are alkenes used for?
To produce polymers and as starting materials to produce other chemicals
What is the functional group of alkenes?
C=C
In a large amount of oxygen, do alkenes combust fully?
Yes
But what happens when there’s a lack of oxygen for alkenes?
They undergo incomplete combustion which produces carbon dioxide and water (as usual) and carbon and carbon monoxide. It burns in the air with a smoky yellow flame and produces less energy.
What happens when an alkene reacts with hydrogen?
Addition reaction - opens up the carbon carbon double bond and forms a saturated alkane. Must be in the presence of a catalyst.