Qualitative Analysis Of Carborn And Hydrogen

Question 1

Carbon Test

Answer 1

Burn the compound in the presence of oxygen.
Carbon is present if carbon dioxide (CO₂) is produced, which turns lime water milky.

Question 2

Hydrogen Test

Answer 2

Combustion in oxygen also tests for hydrogen.
Hydrogen is present if water (H₂O) is produced, which condenses on a cool surface.

Question 3

Copper Oxide Test

Answer 3

Heat the compound with copper(II) oxide.
If carbon is present, it reduces CuO to copper, and CO₂ is released.

Question 4

Lime Water Test

Answer 4

Pass the gases produced from the copper oxide test through lime water.
A white precipitate indicates the presence of carbon.

Question 5

Anhydrous Copper Sulfate Test

Answer 5

Use anhydrous copper(II) sulfate to test for water.
It turns from white to blue if hydrogen is present.

Question 6

Carius Method

Answer 6

Organic compound is heated with fuming nitric acid in a sealed tube.
Carbon is oxidized to CO₂ and hydrogen to water.

Question 7

Liebermann’s Test

Answer 7

For aromatic compounds with nitro groups.
Produces a red or blue color if nitro compounds are present.

Question 8

Beilstein Test

Answer 8

A copper wire is heated and then dipped into the organic substance.
A green flame indicates the presence of halogens, which often accompany carbon and hydrogen.