Organic Chemistry 12 Ethyne Leaving Certificate Chemistry The

Organic Chemistry 12 – Ethyne Leaving Certificate Chemistry

The Alkynes: Cn. H 2 n - 2 Ethyne: C 2 H 2 Carbon-Carbon triple bond 2 Carbons Longest Chain H C C 2 planar carbons H

The Alkynes - Ethyne

Preparation of Ethyne Calcium Dicarbide Ca. C 2 Water H 2 O Acidified Copper Sulfate Solution Cu. SO 4 Water added to calcium dicarbide produces ethyne gas with impurities. These impurities are removed by passing them through acidified copper sulfate solution.

Preparation of Ethyne

Impurities Calcium sulfide solid Calcium phosphide solid Calcium dicarbide Hydrogen sulfide gas Phosphine gas

Preparation of Ethyne The first couple of test tubes collected are usually discarded as they contain displaced air from the reaction boiling tube.

Preparation of Ethyne Balanced Equation for the Synthesis of Ethyne Ca. C 2 + Calcium Dicarbide 2 H 2 O Water C 2 H 2 + Ca(OH)2 Ethyne Calcium Hydroxide

Preparation of Ethyne

Ethyne reaction with acidified potassium permanganate When ethyne gas is bubbled through a solution of acidified potassium permanganate solution a colour change from pink to colourless is observed. This proves that ethyne is an unsaturated compound.

Ethyne reaction with bromine water When ethyne gas is bubbled through a solution of bromine water, colour change from yellow to colourless is observed. This proves that ethyne is an unsaturated compound.

Preparation of Ethyne Ethene is Ethyne Combustion Reaction Balanced Equation for the Combustion of Ethyne C 2 H 2 + 2½ O 2 Turns Limewater Milky 2 CO 2 + H 2 O Turns blue cobalt chloride paper pink

Uses of ethyne Oxy-acetylene Flame for cutting metals Fuel for Carbide Lamps

So far in organic chemistry