Organic Chemistry - Facts

Compound consisting of hydrogen and carbon only.

• plankton die burried under sediment high heat and pressure for millions of years

Used faster than replaced

Sulfur. The combustion of sulfur produces sulfur dioxide, which can cause acid rain.

• Heat crude oil in fractionating column, which is hotter at bottom • Hydrocarbons evapourate and rise up • Large hydrocarbons have more intermolecular forces which take more energy to overcome • So boil at a higher temperature • So condense closer to the bottom

• Small hydrocarbons have fewer intermolecular forces • so less energy to overcome • so boil at a lower temperature • so condenses higher in the column

Alkanes

Contains no C to C double bonds

• Meth- • Eth- • Prop- • But-

CₙH₂ₙ₊₂)

• Boiling point increases • large molecules have more intermolecular forces • so more energy needed to overcome them

• Viscosity increases • Larger molecules have more intermolecular forces So more energy for molecules to move over each other

• Volatility decreases • Larger molecules have more intermolecular forces • So it take more energy to evapourate

• Flammability decreases • Larger molecules have more intermolecular forces • so it take more energy to evaporuate • so less mixing with oxygen

• Ethene • Propene • Butene

CₙH₂ₙ

They contain at least one double bond between carbon atoms.

Test - Add bromine water; Positive result - solution turns from brown to colorless

Burn with a smoky, yellow flame

Cracking is a thermal decomposition reaction.

Large alkane → smaller alkane + smaller alkenes

• Steam cracking requires high temperature and steam • Catalytic cracking requires lower temperature and a catalyst

Exothermic reaction.

Exothermic reaction.