Qualitative detection of 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) sulfate 3. 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 Icon ring test tube beaker Volumetric flask Laboratory iron stand Evaporating dish Alcohol burner

Experiment №1. Qualitative detection of carbon in organic compounds CuO, paraffine CO2 Cu CuSO4 5H2O Ca(OH)2 + CO2 -> -> CaCO3 + H2O CaCO3 Ca(OH)2

Experiment №2. Qualitative detection of hydrogen in organic compounds CuSO4 + 5 H2O -> CuSO4 * 5 H2O Cu CuO H2O Paraffin C23H48 + 70CuO -> 70Cu + 23CO2 + 24H2O 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.

Experiment: Qualitative detection of carbon and hydrogen in organic compounds CuSO4 + 5 H2O -> CuSO4 * 5 H2O CuO, paraffin Cu CO2 CuSO4 5H2O Ca(OH)2 + CO2 -> -> CaCO3 + H2O CaCO3 Ca(OH)2 C23H48 + 70CuO -> 70Cu + 23CO2 + 24H2O

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

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. H2O 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. SO2 C H O CO2 oxygen reducing agent Blue vitrol CO Cl copper malaxite oxidizing agent 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) oxide 5. Unaqueous copper (II) sulfate becomes blue because ……………

Test № 2 Put correct word instead of dots hydration C8H18 dehydration hydrogenation C23H48 C23H46 H O S Cl C CCl4 CHCl3 CH4 Cu 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 ….