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Flashcards in Crude Oil Deck (15)
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1
Q

What is crude oil?

A

Crude Ouil is a complex mixture of hydrocarbons. A fossil fuel consisting of the remains of ancient biomass. It is a Finite resource as it cannot be replaced as it is used up.

2
Q

What is a hydrocarbon?

A

A compund made up exclusively of hydrogen and carbon atoms.

3
Q

What is a homologous series?

A

Series of compounds with same general formula, same functional groups and similar chemical properties

4
Q

Explain how fractional distillation of crude oil takes place

A
  • Crude oil is heated and vaporised.
  • Vapor rises up the fractionating column (tower).
  • The column is hotter at the bottom and cooler at the top.
  • Hydrocarbons cool as they go up the column and condense at different heights, as they have different boiling points.
  • Large molecules, high boiling points
  • collected at the bottom.
  • Small molecules, low boiling points
  • collected at the top.
  • This gives fractions, which can be used in various ways
5
Q

What is cracking?

A

Whe large hydrocarbons are thermally broken down into smaller and useful molecules.

6
Q

What type of reaction is cracking?

A

Thermal decomposition

7
Q

What are the conditions for cracking?

A

Reactant heated to vapor, passed over a hot catalyst (catalytic cracking) or heated to vapor, mixed with steam and heated to high temperatures (steam cracking)

8
Q

How are the products of cracking used?

A

The products are alkanes and alkenes - used as polymers and for fuels

9
Q

As the molecules in hydrocarbons become bigger what changes occur?

A
  • Boiling point increases: Large molecules are attracted to each other more strongly than smaller ones so more energy is neede to break these stronger intermolecular forces
  • The liquids become less volatile: The bigger the hydrocarbon, the more slowly it evaporates at room temperature
  • The liquids become more viscous is and flow less easily: liquids containing small hydrocarbons molecules are runny. Those containing large molecules flow less easily because of stronger forces of attraction between their molecules
  • The liquids become darker in colour
  • Bigger hydrocarbons do not burn as easily as smaller ones. This limits the use of the bigger ones as fuels
10
Q

Name all the fractions in crude oil in order

A
11
Q

Give an example of a catalyst used in cracking

A

Aluminium oxide

12
Q

How is incomplete combustion caused?

A

If there isn’t enough air for

13
Q

Why is carbon monoxide dangerous?

A
14
Q

How is Acid rain formed?

A

Acid rain is formed when water and oxygen in the atmosphere react with soulful dioxide to produce sulfuric acid (H)

15
Q

Why is Acid rain a problem?

A
  • Limestone buildings and statues are damaged by acid rain
  • Acid rain reduces growth of trees and growth or kills trees and crops
  • Acid rain lowers the pH of river water killing fish