Expt : 1 Melting point of ice and boiling point of water

Aim :

To determine the melting point of ice and boiling point of water.

Materials required:

Two thermometers , boiling tube, a glass rod, two iron stands, a bunsen burner , wire gauze ,
beakers, tripod stand, distilled water, ice cubes prepared from distilled water.

Procedure

A. To determine the boiling point of water

(i) Take 25 – 30 ml of water in a boiling tube and add few pumice stones to it.

(ii) Clamp the boiling tube on iron stand with one holed cork. Fix the thermometer in one hole.

(iii) Place the thermometer above the water in the flask and record its temperature.

(iv) Place a burner under the boiling tube

(v) Read the temperature when the water boils. Record the readings at time interval of 1 minute.

B.To determine the melting point of ice

(i) Take a beaker half filled with the dry crushed ice obtained from distilled water.

(ii) Suspend a celsius thermometer from the clamp stand such that the bulb of the thermometer is
completely surrounded by ice.

(iii) Read the thermometer reading and record the temperature after every 1 minute till the ice
melts ( iv) Note the readings in the observation table.

Result:

1. Boiling point of water is ______

2. Melting point of ice is ______
3. Once the boiling point of water / melting point of ice is attained the temperature remains
constant for sometime.

Precautions

1.Choose a better quality thermometer whose graduated scale is clearly readable.

2.While reading the thermometer the eye level should be parallel with mercury level.

3.Dip only the bulb of thermometer into water / ice.

4.Thermometer should not touch the walls of beaker or boiling tube.

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Observation Table:

Boiling point of water

S.No. Temperature when water starts Temperature when water Boiling point of water
boiling (t10c) continues to boil till (t1+t2/2)0C
constant (t20c)
1.
2.

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Observation Table:

Melting point of ice

S.No. Temperature when ice starts Temperature when ice Melting point of ice
melting (t10c) melts completely (t20c) (t1+t2/2)0C
1.
2.
Expt : 2 Solution, Colloids, Suspension

Aim: To prepare

(a) a true solution of common salt

(b) a suspension of sand in water
(c) a colloidal solution of starch in water

and distinguish between these on the basis of (i) transparency (ii) filtration criterion (iii)
stability

Materials required : Beakers , a glass rod, test tube stand, three test tubes , three funnels, filter
papers, a small torch, china dish, an iron stand.

Chemicals required: Common salt, soil, starch and distilled water.

Procedure:

A.To prepare a true solution of common salt

Take a clean and dry beaker, pour 100ml of distilled water in it and add dry common salt in it. Stir
the content with a glass rod .Common salt dissolves completely to form a true solution.

B.To prepare a suspension of soil

Take 100 ml of distilled water in a beaker , add 10g of soil to it. Stir the mixture with a glass rod.
Soil does not dissolve in water but forms a suspension.

C.To prepare colloidal solution of starch

Take about 1g of starch in a china dish, pour 10ml of distilled water in the dish and stir the mixture .
Now take 90ml of hot boiling water. Stir the contents of the china dish continuously and pour the
contents in the boiling water. Allow the contents to cool.

D.To distinguish the above formed solutions on the basis of transparency, filtration criterion and
stability:

(i)Transparency:

Take 3 test tubes with a colloid, suspension and true solution in each respectively. Paste a white
paper with a tick mark on one side of each test tube. Look at the tick mark through the contents of
the three test tubes from the other side . Check for the transparency of tick mark. Record your
observations.

(ii) Filtration criterion :

Take 3 test tubes in test tube stand , place a funnel over each test tube . Fix the filter paper in the
funnel and check for the filtration criterion. Record your observations.

(iii)Stability criterion :

Take 3 test tubes with a colloid, suspension and true solution in each respectively. Shake all the
test tubes and keep them in the test tube stand, allow it to stand for 5 minutes.

Record your observations.

Precautions
 1. Use test tube holder for boiling of water.
2. Do not waste the chemicals and distilled water. Use it wisely.
3. Always stir the contents in the test tube nicely and gently.
4. Use only distilled water to make solutions.

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Observation Table:

S.No. Property True solution Colloidal solution Suspension

1. Size of particles < 10-9m Between 10-9m-10-6m >10-6m
2. Nature Homogeneous Appears homogeneous Heterogeneous
but is heterogeneous
3. Visibility Solute particles are Solute particles are Solute particles
invisible to naked eye invisible to naked eye are visible to
and under microscope but can be viewed naked eye
under powerful
microscope
4. Stability Solute particles do not Solute particles do not Solute particles
settle down and are settle down and are settle down and
stable stable (on are unstable
centrifugation the
particles can settle)
5. Filtration Solute particles can Solute particles passes Solute particles
pass through filter through filter paper cannot pass
paper and no residue and no residue is seen through filter
is seen on filter paper on filter paper(but the paper and
particles cannot pass residue is
through parchment collected on filter
membrane) paper
6. Transparency Transparent Translucent Opaque
Expt : 3 Mixture and compound

Aim:

To prepare a mixture and a compound using iron filings abd sulphur powder and distinguish
between these on the basis of

(i)Appearance i. e. Homogeneity and heterogeneity

(ii)Behaviour towards a magnet

(iii)Behaviour towards carbon -di- sulphide as a solvent

(iv)Effect of heat

Materials required:

Test tubes , test tube stand , test tube holder,hard glass test tube, bunsen burner, tripod stand, wire
gauze, magnet, china dish and a watch glass.

Chemicals required:

Iron filings,sulphur powder, carbon -di- sulphide.

Procedure

A.Preparation of a mixture of iron and sulphur powder .

Take a pinch of iron filings and two pinch of sulphur powder, mix them thoroughly. The product
obtained is mixture of iron and sulphur. Keep it in a watch glass.

B.Preparation of the compound of iron and sulphur.

Take a pinch of iron filing and a pinch of sulphur powder in a hard glass test tube.Hold it in a test
tube holder, heat it on the flame till the contents glow. The reaction between sulphur and iron
filings is seen in tbe test tube and iron sulphide is formed . Transfer the compound formed in s
watch glass.

Precautions

1.Heat the mixture of iron and sulphur in hard glass tube or in a china dish.

2. Heating activity should be done carefully.

3.Carbon di sulphide is flammable , keep it away from flame.

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Observations:

S.No. Experiment Observations Inference

1. Observe for appearance: Watch glass A shows A is heterogeneous

heterogeneous mixture and mixture and B is
B shows a black mass of homogeneous substance
homogeneous substance
2. Action with magnet: Iron filings cling to magnet Constituents of mixture A
A bar magnet is rolled from watch glass A but not in can be separated physically
over both the watch B but not in B
glasses A and B
3. Behaviour towards In test tube A sulphur Components of mixture
carbondisulphide: dissolves in carbon disulphide can be separated by
Take cmponents from and iron filings settle down.In physical means in A
watch glass A and B in test tube B nothing dissolves. A is mixture
separate test tubes and B is compound
add carbon di sulphide
in it.
4. Effect of heat On heating mixture from The mixture components
watch glass A the from watch glass A react
components react together together to form a
to form a compound but no compound but no change is
change is seen in compound seen in compound from
from watch glass B watch glass B