Laboratory Work №1

Qualitative detection of

carbon,

hydrogen,

chlorine

in organic compounds

PROCEDURE

1. Put copper (II) oxide and paraffin into the test tube, then heat it carefully until paraffin melts and shake the test tube.2. Place the test tube into the laboratory iron stand and add some copper (II) sulfate3. Close the test tube by a bent delivery test tube the other end of which is dipping into lime water contained in flame.

Laboratory equipment

Laboratory iron stand

Icon ring

beaker Volumetric

flask

Alcohol burner

test tube

Evaporating dish

Experiment №1. Qualitative detection of carbonin organic compounds

CO2

Ca(OH)2

Ca(OH)2 + CO2 -> -> CaCO3 + H2O

CaCO3

CuSO4

CuO, paraffineCu

5H2O

Experiment №2. Qualitative detection of hydrogen in organic compounds

H2O

CuSO4 + 5 H2O -> CuSO4 * 5 H2O

When mixture of paraffin and copper (II) oxide is heated alkanes are oxidized to carbon dioxide and water. Water forms hydrate with copper (II) sulfate which has blue color. Copper (II) oxide is reduced to red copper. So in paraffin hydrogen exists.

CuO

Paraffin

Cu

C23H48 + 70CuO -> 70Cu + 23CO2 + 24H2O

Experiment: Qualitative detection of carbon and hydrogen in organic compounds

CO2

Ca(OH)2

Ca(OH)2 + CO2 -> -> CaCO3 + H2O

CaCO3

CuSO4

CuO, paraffinCu

5H2O

C23H48 + 70CuO -> 70Cu + 23CO2 + 24H2O

CuSO4 + 5 H2O -> CuSO4 * 5 H2O

Your observations

• Copper (II) oxide reduced to copper, so we observe change in color from black to red. C23H48 +70 CuO -> 23 CO2 + 24H2O + 70 Cu

• Colorless copper (II) sulfate changed its color to blue because of formation of copper (II) sulfate pentahydrate. CuSO4 + 5H2O -> CuSO4 * 5H2O

• Carbon dioxide formed as a result of reaction gives precipitate of the carbonate by passing into limewater solution. Ca(OH)2 + CO2 -> CaCO3 + H2O

H2O

Experiment № 3. Detection of carbon in sugar (sucrose) by carbonization test

Put some amount of sugar into an evaporation dish . Then heat it. Sugar carbonized.

Sugar carbonizes i.e. carbon as pure element coke is produced t

C12H22O11 -> 12 C + 11 H2O

Experiment №4. Qualitative detection of chlorine in organic compounds – Beilstein test

Heat a copper wire in a bunsen flame until the color is non-luminous

Insert the copper wire into the organic solid substance to be analyzed

Heat the copper wire again.

Copper forms copper (II) chloride and the flame will take the characteristic green blue color.

Test № 1 Put correct words instead of dots.

1. Lime water forms precipitate when …….. passes through the solution

2. Formation of precipitate proves the existence of ……

3. In the reaction copper (II) oxide - …………

4. …. is formed from copper (II) oxide5. Unaqueous copper (II) sulfate

becomes blue because ……………

H

malaxite

CO2

Cl

oxygenO reducing agent

Blue vitrol

SO2

oxidizing agent

C

CO copper

Test № 2 Put correct word instead of dots

1. The color of copper (II) sulfate changes as a result of ………..

2. Molecular formula of paraffin …….3. Formation of CuSO4* 5H2O proves

existence of … 4. The formula of tetrachloromethane ……. 5. The flame assumes the green – blue color

because of the presence ….

CH4

C8H18

S CCl4

dehydration

H CHCl3

hydrogenation C23H48

C23H46

hydration

O CuCl C