Grade 9 Chemistry Practicals.

1. Experimment No.1
1. Preparation of:-
a. A true solution of common salt ,sugar and alum.
b. A suspension of oil, chalk powder and fine sand in water.
c. A colloidal solution of starch in water and egg albumin/milk in water and
distinguish between these on the basis of :-
(i) Transparency (ii). Filtration criterion (iii). Stability.

Aim:
To prepare a suspension of soil, chalk powder and fine sand in water and distinguish between these
on the basis of transparency, filtration criterion, and stability.

Theory:
The particle size in suspension is on the order of 10-5 cm or greater, which may be observed with the
naked eye or under a microscope. The suspensions were not particularly stable, and after a few
minutes, the suspended particles settled down.

Properties of Suspension:
1. It is a mixture that is heterogeneous in nature.
2. Particles with a diameter greater than 1000 nm (10-6 m) can be seen with the naked eye.
3. The suspension particles scatter a beam of light in their suspended state, which is known as
the Tyndall effect.
4. It’s in a state of instability.
5. Filtration could be used to separate the particles.
6. It is opaque in nature.

Materials Required:
Beakers, Test tubes, Soil, Chalk powder, Fine sand, Glass Rod, Water.
Procedure:
Step 1: Fill three beakers with 100 mL of water and label them A, B, and C, respectively.
Step 2: In each beaker, 10g of fine soil (without litter), fine chalk powder, and fine sand are added
separately.
Step 3: Using the glass rod, stir the solution.
Step 4: Label the test tubes as A, B, and C to identify the solutions.

Observation Table:
Property Experimental Procedure Observation Inference

Each test tube has a small strip

of cellophane paper glued on it, From the other side
and the coloured paper of each of the test tube, the
test tube can be seen from the coloured spot is not A suspension is
Transparency other side. visible. opaque in nature.

The filter paper Filtration can

shows a particle separate the
suspension, yet the suspended
Filtration Filtrate the contents of test filtrate is a clear components of a
Criterion tubes labelled A, B, and C. liquid. suspension.

The suspensions are

Solid particle not stable and
Allow 20-25 minutes for the test settlement can be contain heavy
tubes to rest without being observed at the components
Stability disturbed. bottom. deposited.

Results and Discussion:

Suspensions are opaque in nature. On filtration, they left residue on the filter paper. The filtrate is
clear or translucent in appearance.

Precautions to be taken during the experiment:

(i) Handle the materials and solutions with care.
(ii) While filtering a solution, pour the contents into the funnel using a glass rod.
(iii) Do not disturb the sample during the stability test.
 Experiment No.2
Preparation of :-
(i) A mixture (ii). A compound.

Aim
The experiment aims to prepare a mixture and compound using iron filings and sulphur powder and
distinguish them based on their appearance, i.e., uniformity and non-uniformity, behaviour towards a
magnet, behaviour towards carbon disulphide as a solvent and effect of heat.

Theory
A matter is anything that occupies space and has mass. Based on the composition of the substance,
we can further classify matter into two kinds, i.e. mixture and pure substance. We can further divide
the mixture into homogenous and heterogeneous mixtures and pure substances into elements and
compounds.

Material Required
The apparatus and materials required for this experiment are as follows:

• Bunsen burner
• Tripod stand
• Wire gauze
• Test tube stand
• Hard glass test tube
• Test tubes
• Test tube holder
• China dish
• Watch glass
• Magnet

Procedure
1 . Preparation of iron filings and sulphur powder mixture

• Foremost, we took a pinch of iron filings and sulphur powder and mixed it thoroughly.
• The result was a mixture of iron filings and sulphur powder.
• We kept the mixture on a watch glass.
2 . Preparation of iron filings and sulphur powder compound

• Foremost, we took a pinch of iron filings and sulphur powder in a hard glass test tube.
 • After that, we heated the reaction mixture on flame.
• The result was a mixture of iron and sulphur powder. A reaction between iron and sulphur
was observed, leading to the formation of the iron sulphide compound.
• We kept the compound on a watch glass.

Observation and Inference

S.
No. Experiment Observation Inference

Appearance, i.e., Watch glass A shows a

homogeneity and heterogeneous mixture. In
heterogeneity: Observed the contrast, watch glass B A is a heterogeneous
appearance of both mixture shows a black mass of the mixture, while B is a
1. and compound. homogenous substance. homogenous substance.

Iron filings cling to the Constituents of A could be

Behaviour towards a magnet: magnet from watch glass A, separated physically by
A bar magnet was rolled over but we observed no such rolling a magnet, while we
2. both watch glasses A and B. behaviour in B. can not separate compound.

Behaviour towards Carbon In test tube A, sulphur

disulphide as a solvent: Took dissolves in carbon Constituents of A could be
components from watch disulphide, and iron fillings separated physically by
glass A and B in separate test settle down. At the same dissolving in carbon
tubes and added Carbon time, we observed no such disulphide, while we can not
3. disulphide. behaviour in B. separate compounds.

The mixture components

On heating mixture from from watch glass A react
watch glass A, iron fillings together to form a
and sulphur react together to compound, while we
Effect of heat: Heated both form a compound, while we observed no change in the
4. mixture and compounds. observed no change in B. watch glass B.

Precautions
• Heat the iron filings and sulphur powder mixture in a china dish or a hard glass.
• Don’t inhale gases released during the experiment.
• Keep carbon disulphide away from the flame.
 Experiment No.3
To Identify the following reactions :-

1. Iron with copper sulphate solution in water.

2. Burning of magnesium ribbon in air.
3. Zinc with dilute sulphuric acid.
4. Heating of copper sulphate.
5. Sodium sulphate with barium chloride in the form of their solutions in water.

Materials Required
Test tubes, test tube stand, test tube holder, a pair of tongs, Bunsen burner.

Chemicals Required
Iron filings, copper sulphate solution, magnesium ribbon, zinc granules, dilute
sulphuric acid, sodium sulphate and barium chloride solutions and copper
sulphate crystals.

Procedure

Iron with copper sulphate solution in water

Reaction. Fe(s) + CuSO4(aq) FeSO4 (aq) + Cu(s).

Burning of magnesium ribbon in air

 Reaction

(i) 2Mg(s) + O2(g) 2MgO (s)

(ii) MgO (s) + H2O(l) Mg(OH)2 (aq)

Zinc with dilute sulphuric acid.

Reaction: Zn(s)+H2SO4(aq) ⟶ ZnSO4(aq)+H2(g)

Heating of copper sulphate salt

Reaction

On heating CuSO4.5H2O Crystals, CuSO4.5H2O CuSO4 + 5H2O

Blue colour White(anhydrous)

On adding water to white powder of anhydrous copper sulphate,

CUSO4 (s) + H2O(l) CuSO4(aq)

White Blue solution

Reaction of sodium sulphate and barium sulphate solutions.

Reaction

Na2SO4(aq) + BaCl2 (aq) 2NaCl (aq) + BaSO4(s)

Precautions

1. Use all the chemicals in very less quantity.

2. Use test tube holder for heating.
3. Clean magnesium ribbon with sand paper and use fire tongs for holding
magnesium ribbon.
4. Handle the acids and alkalies carefully.
 Experiment No.4
To determine the melting point of ice and boiling point of water.
Aim
To determine the melting point of ice and boiling point of water.

Theory

1. Melting Point: The temperature at which the solid changes into liquid at the
atmospheric pressure is called melting point. For example, ice melts at 0°C to
form water.
2. Boiling Point: The temperature at which the liquid boils and changes into
gaseous state at the atmospheric pressure is called boiling point. For example,
water boils at 100°C to form water vapour (at 76 cm pressure).
3. Latent Heat of Fusion: The heat energy absorbed during the melting of ice is
stored in the water formed, this energy is called latent heat of fusion. The amount
of heat energy that is required to change 1 kg of a solid into liquid at atmospheric
pressure at its melting point is known as the latent heat of fusion.
4. Latent Heat of Vaporisation: The heat energy absorbed by water when it
changed its phase to steam, this hidden heat is called latent heat of vaporisation.

MaterialRequired
Two thermometers, (Celsius scale), 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.

1. Take 25-30 ml of water in a boiling tube and add few pumice stones to it.
2. Clamp the boiling tube on iron stand with two holed cork, in one hole fix the
thermometer and in the other one fix the delivery tube.
3. Place the thermometer above the water in the flask as shown in the figure and
record its temperature.
4. Place a burner under the boiling tube.
 5. Read the temperature and record it in the given observation table till the water
boils. Record the reading after the time interval of 1 minute.

Observation Table

Result

1. Boiling Point of water is 100 °C.

2. Once the boiling point is attained the temperature reading on thermometer does
not change for sometime.

(B)To determine the melting point of ice.

1. Take a beaker half-filled with the dry crushed ice obtained from distilled water.
2. Suspend a Celsius thermometer from the clamp stand such that the bulb of the
thermometer is completely surrounded by ice.
3. Read the thermometer reading and record the temperature after every 1 minute till
the ice melts and the thermometer reading remains stationary for 2 minutes.
4. Note the readings in the observation table.
 1. Note the readings in the observation table.

Observation Table

Result

1. Melting point of ice is 0 °C.

2. Once the melting of ice begins the temperature remains constant for some time.

Precautions

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

2. Record the temperature in whole numbers.
3. While reading the thermometer the eye level should be parallel with mercury level.
4. Dip only the bulb of thermometer into water/ice.
5. Thermometer should not touch the walls of beaker or boiling tube.
 Experiment No.5
Verification of law of conservation of mass in a chemical reaction

Aim:
To verify the law of conservation of mass in a chemical reaction.

Materials Required:
Two watch glasses, beakers, weighing balance and glass rod.

Chemicals Required:
Distilled water and Barium chloride and Sodium sulphate.
BaCl2(aq) + Na2SO4(aq) BaSO4 (s) + 2 NaCl (aq)

Procedure:
1. Make a 5% solution of any of the X and Y compounds listed.
2. In a conical flask, place a small amount of Y solution and a small amount of X solution.
3. As illustrated in the diagram, carefully suspend the ignite tube in the flask. The test tube
solution must not flow into the flask.
4. Cover the flask with a cork.
5. Carefully weigh the flask and its contents.
6. Now gently tilt and swirl the flask to combine the solutions X and Y.
7. Re-weigh the conical flask.
8. Make a note of your findings.
9. Note the mass of the conical flask before reaction.

Observations:
• Initial weight of conical flask + ignition tube with X and Y solutions =……g
• Weight of conical flask + ignition tube when solution X and Y are mixed and reaction has
taken place =……. g.
• The mass of the reactants equals the mass of the products.

Chemical Equation
BaCl2(aq) + Na2SO4(aq) BaSO4 (s) + 2 NaCl (aq)

Result:
• Mass of reactants equals mass of products
• In a chemical reaction, there is no mass loss.
Precautions:
1. When using the weighing machine, use caution.
2. Only use distilled water to make the solution.
3. Do not taste any chemical.
4. When solution X and Y have been combined, place a cork in the bottle.
5. To calculate the resultant mass of the product, subtract the mass of the conical flask + cork.
6. When the chemicals (reactants) are mixed, cork should be used to prevent the gas, or
vapours, from escaping. The law is verified only in closed systems.

While recording the initial mass, be sure the chemical does not run out of the ignition tube