Alkanes

Get Revising

Created by: rubyboast
Created on: 06-04-18 19:22

View mindmap

Alkanes
- Crude Oil and Hydrocarbons
  - crude oil
    - formed over millions of years from the fossilised remains of plankton
    - found in a porous rock in the earths crust
    - a finite (non - renewable) resource that is used to produce fuels and other chemicals
  - most of the compounds in crude oil are hydrocarbons
    - hydrocarbons = molecules made of only carbon and hydrogen atoms
  - hydrocarbon molecules vary is size
    - the larger the hydrocarbon
      - more viscous
      - higher its boiling point
      - less volatile it is
      - less easy it ignites
- Fractional Distillation
  - crude oil can be separated into different fractions by fractional distillation
    - each fraction contains hydrocarbon molecules with a similar number of carbon atoms
  - most of the hydrocarbons obtained are alkenes
- Alkenes
  - carbon atoms are linked to four other atoms by single bonds
  - saturated hydrocarbons - because they contain the maximum amount of bonds possible
  - fairly unreactive, but they burn well
  - CnH2n+2
  - shorter- chain alkanrs release energy more quickly by burnig, so there is a greater demand for them a s fuel
- Burning Fuels
  - most are compounds of carbon and hydrogen
    - many also contain sulfur
  - combustion (burning) of hydrocarbon fuels
    - both carbon and hydrogen are oxidised
    - energy is released
    - waste products are produced - atmosphere
  - if combustion not complete = carbon monoxide, solid particles and unburnt fuels produced