LAB ACTIVITY FOR CLASS IX

EXPERIMENT 1 

Separation of Mixtures by Sublimation

Aim: To separate the mixture by sublimation.

Apparatus: China dish, Mixture of ammonium chloride, funnel, stove.

Procedure:

1. Take one tablespoon of common.

2. Add one tablespoon of ammonium chloride to common salt and mix them.

3. Take the mixture into a china dish. Take a glass funnel that is big enough to cover the dish.

4. Take a piece of cotton and close the mouth of the funnel.

5. Now place the inverted funnel over the china dish.

6. Keep the dish on the stand of stove and heat for some time and observe the walls of the funnel.

Observations:

1. Initially we find vapours of ammonium chloride and then solidified ammonium chloride on the walls of the funnel.

2. The table salt remains in the dish.

Analysis:

As the ammonium chloride is sublime overheating, it will directly get converted into vapour and

this vapour will again condense at the upper colder part of the funnel to form solid ammonium 

chloride. In this way, the mixture of table salt and ammonium chloride can be separated by the 

method of sublimation.

EXPERIMENT 2

Separation of mixtures by evaporation of water

Aim: Separation of mixtures by the evaporation of water.

Apparatus: Watch glass, ink, beaker, burner.

Procedure:

1. Take a beaker and fill it to half its volume with water.

2. Keep a watch glass on the mouth of the beaker.

3. Put few drops of ink on the watch glass.

4. Heat the water in the beaker and observe the watch glass.

5. The steam thus formed will heat up the ink.

Observations:

1. The water present in the ink evaporates and ultimately a residue is left in the watch glass. This is the dye.

Conclusion: 

Ink is a mixture of a dye in water.

We can separate the components in the ink using evaporation.

EXPERIMENT 3

Paper Chromatography

Aim: Separating the compounds of ink using paper chromatography.

Apparatus: Beaker, rectangular shaped filter paper, black marker (non permanent), water,

pencil and cello tape.

Theroem: Chromatography, technique for separating the components, or solutes, of a mixture on the basis of the relative amounts of each solute distributed between a moving fluid stream.

Procedure:

1. Draw a thick line just above the bottom of the filter paper using the marker.

2. Pour some water in the beaker and hang the paper strip with the help of a pencil and cello tape in such a way that it should just touch the surface of water.

3. Make sure that the ink line or mark does not touch the water.

4. Allow the water to move up the paper for 5 minutes and then remove the strip from water. Let it dry.

Observations:

1. Water flows slowly upwards from the filter paper.

2. The solvent should immediately start 

moving up the paper strip, carrying the ink

pigments with it.

Conclusion:

Chromatography is one of many techniques to

separate the compounds in a mixture and to

identify unknown substances. We separate the

various ink pigments from the black ink.

Precautions:

1. Make sure that the ink line or mark does

not touch the water.