Organic Chemistry

• Name and draw the formula of alkanes

  Methane (4H,1C)Ethane (6H,2C)Propane (8H,3C)Butane(10H,4C)
• Tests for alkanes

  -add bromine water (orange)

  -alkane stays orange
• What is crude oil?And how is it made?

  -Mixture of hydrocarbons (only hydrogen and carbon)-made of the remains of an ancient biomass consisting mainly of plankton
• What are alkanes and formula

  saturated hydrocarbons

  Cn H2N+2
• What is cracking and what type of reaction is it?

  thermal decomposition -in which large alkanes are broken down into smaller alkanes & alkenes
• descibe the process of fractional distillation?

  -crude oil is heated to vapourise

  -enters the column which is hot at the bottom and cold at the top

  -the hydrocarbons moves up the column until it reaches its boiling point

  -where it condenses and collects
• What are the differnt states of condition in cracking?

  catalytic cracking -needs a catalyst at a high temperature then heated to very high temperature
• What are the properties of hydrocarbons


  Properties depends on the size of molecules

  -Vicosity and boiling point -increases with chain length

  -Flammability-decreases chain length
• What is the equation for complete combustion?

  fuel+oxygen=carbon dioxide+water
• test for alkenes

  -add bromine water

  -alkene orange to colourless

  -becuse of the double or triple bonds break with the carbon inside bromine
• What is the equation for complete combustion?

  fuel+oxygen=carbon dioxide+water
• why do alkene's colour change in bromine water

  the double or triple bonds break with the carbon inside bromine