Chemistry - Ethene and Ethyne

Elimination Reaction

dehydration of ethanol

Elimination Reaction

a double bond is formed and a small molecule is removed

Aluminium Oxide

(white powder)

dehydrating agent in preparation of ethene

Glass Wool

is used to hold ethanol in place in the preparation of ethene

Physical Properties of Ethene

1. colourless

2. sweetish smell

3. less dense than air

4. insoluble in water (non polar)

Chemical Properties of Ethene

1. unsaturated compound

2. reacts by addition reactions

Bromine Water

test for unsaturation in organic compounds

Red/Brown to Colourless

colour change when an unsaturated compound, e.g. ethene or ethyne, is bubbled into bromine water

Acidified KMnO4

safer, alternative test for unsaturation

Unsaturated Compounds

decolourise acidified KMnO4 , e.g. ethene and ethyne

Exothermic Reaction

preparation of ethyne

Calcium Carbide

is boiled into CuSO4 in the preparation of ethyne

Copper Sulphate

removes impurities, such as PH3, in the preparation of ethyne

PH3

produced by the reaction of H2O with Ca3P2 and H2S from CaS, in the preparation of ethyne

Ethyne

burns with a sooty flame due to high carbon content