organic chemistry: crude oil

Each fraction consists of groups of hydrocarbons of _______ chain lengths. They have similar _____and ________, which (depends on the number of carbon atoms in the chain)

similar chain lengths

similar properties and boiling points, which depend on the number of carbon atoms in the chain

label diagram

each section, name of fraction that comes out

at least one use

top one is methane, so for stoves

define crude oil

mixture of hydrocarbons with different chain lengths

describe how fractional distillation separates crude oil into fractions [5]

crude oil boiled/vaporised (in furnace);

column is hot at the bottom and cool at the top;

hydrocarbon vapours rise up the column

they condense back into a liquid when their boiling point is reached

smaller / lighter molecules move higher up the column

fractions with lower boiling points move further up column

smaller / lighter molecules have lower boiling points

liquid fractions are removed

crude oil is heated to a high temperature, causing it to vaporize. The vapor is then passed through a series of trays or columns, with each tray or column being at a slightly lower temperature than the previous one. As the vapor cools, different hydrocarbons condense into liquids at different temperatures, allowing them to be separated into fractions.

how properties of the hydrocarbons change as you go up the column

going up the column

• carbon chain lengths get smaller

• more volatile

• lower boiling points

• lighter

  • less viscous (flow easier)

why is crude oil considered a finite resource

because it takes so long to form (millions of years)

define fuel

a substance that, when burned, releases energy

name	use
liquified petroleum gas
petrol
kerosene
diesel
heavy fuel oil
bitumen

how is sulfur dioxide made from burning hydrocarbons

what is the harm caused

produced by combustion of hydrocarbons containing sulfur impurities

dissolves in rain water to form sulfuric acid, and falls as acid rain

this damages rivers and lakes and corrodes limestone

how is nitrogen oxide made from car engines/exhausts

what is the harm caused

when oxygen and nitrogen react at high temperatures

will enter atmosphere, dissolve in rain water to form acid rain

can cause photochemical smog, can cause respiratory problems

sulfur dioxide to acid rain eq

2SO₂ (g) + O₂ (g) + 2H₂O (l) → 2H₂SO₄ (aq)

nitrogen dioxide to acid rain eq

2NO₂ (g) + H₂O (l)  → HNO₂ (aq) + HNO₃ (aq)

nitrous and nitric acids contribute to acid rain