JOHNSON GRAMMAR SCHOOL [Senior Secondary School Affiliated to CBSE} Raghavendra Nagar, Nacharam, Hyderabad
PRACTICALS
TERM -1
1. Determination of the melting point of ice and the boiling point of water 2. Preparation of:
a) a true solution of common salt, sugar and alum b) a suspension of soil, 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
• transparency
• stability 4. Preparation of
a) A mixture b) A compound using iron filings and sulphur powder and distinguishing between these on the basis of:
(i) appearance, i.e., homogeneity and heterogeneity (ii) behaviour towards a magnet (iii) behaviour towards carbon disulphide as a solvent (iv) effect of heat
5. Separation of the components of a mixture of sand, common salt and ammonium chloride (or camphor).
6. Perform the following reactions and classify them as physical or chemical changes: a) Iron with copper sulphate solution in water b) Burning of magnesium ribbon in air c) Zinc with dilute sulphuric acid d) Heating of copper sulphate crystals e) Sodium sulphate with barium chloride in the form of their solutions in water
TERM - 2 6. Verification of the law of conservation of mass in a chemical reaction.
D a te
: 0 2 .-0
0 2 1
EXPERIMENT NO -1
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.
Conditions Affecting Melting Point and Boiling Point
Materials Required 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 some time.
(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.
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.
Olabs links for the SEA of a) finding M P of ice: https://youtu.be/zk4vhD2X4Ew
https://youtu.be/38QZEsB2xJM
VIVA VOCE (NOT TO BE WRITTEN IN RECORD)
Question 1: What is the melting point of pure water ice cubes? Answer: 0°C. Question 2: What is the boiling point of pure water? Answer: 100°C. Question 3: At what temperature is the density of water maximum? Answer: At 4°C. Question 4: At what temperature will you get the latent heat of fusion for water? Answer: At 0°C. Question 5: What is the latent heat of fusion of ice? Answer: 336 kJ/kg.
PRACTICAL BASED QUESTIONS Question 1: What is the principle of working of a pressure cooker? Answer: In pressure cooker the pressure is increased. The water boils at temperature more than 100°C. Question 2: Which of the two contains more heat energy, water at 100°C or steam at 100°C? Answer: Steam at 100°C, contains more heat energy. Question 3: When ice and cold water both are at 0°C then why does ice floats on water? Answer: Density of ice is less than water. Question 4: In cold countries why do people sprinkle common salt over it? Answer: The ice melts faster when salt is sprinkled over it and the clearance of ice from the path becomes easier and faster impurities decreases the melting point. Question 5: State the temperature at which water and ice co-exist. Answer: Water and ice co-exist at 0°C/ 273 K.
NCERT LAB MANUAL QUESTIONS Question 1: Why is the bulb of thermometer kept above the surface of water while determining the boiling point of water? Answer: The water boils and the steam is formed at its boiling point. Hence to get the accurate boiling point of water the thermometer is placed above the surface of water. Question 2: Why does the temperature remain unchanged until the entire solid changes into liquid even if we are heating the solid? Answer: The temperature remains unchanged until the entire solid changes into liquid even if we are heating the solid; it is because the heat is used up by the molecules in overcoming the force of attraction. Question 3: Why do we fix a two holed-cork in the round bottom flask while determining the boiling point of water? Answer: The two holed-cork is fixed in the round bottom flask while determining the boiling
point of water. Through one hole fix the thermometer and through the other hole the delivery tube is fixed which allows the steam to pass through.
MULTIPLE CHOICE QUESTIONS (MCQs) Questions based on Procedural and Manipulative Skills
Question 1: When do ice and water co-exist under atmospheric pressure? (a) At 0°C (b) below 0°C (c) above 0°C (d) at 5°C. Question 2: For determining the melting point of ice we should prefer. (a) ice made from distilled water (b) ice made from tap water (c) dry crushed ice mixed with salt (d) a mixture of ice and salt. Question 3: For the accurate determination of the boiling point of water, we use (a) tap water (b) distilled water (c) salt solution (d) sugar solution. Question 4: If pure water is heated it will start boiling at: (a) 173 K (b) 100 K (c) 373 K (d) 273 K. Question 5: While determining the boiling point of water, pumice stone pieces are added to (a) spread the heat uniformly (b) prevent loss of heat energy (c) avoid bumping (d) avoid cracking of the glass container. Question 6: Which of the following would you choose to determine the melting point of ice in your laboratory? (a) Dry crushed ice (b) Ice cubes (c) Ice added to water (d) Slab of ice. Question 7: Which of the following apparatus is required to determine the boiling point of water? (a) Tripod stand, conical flask, thermometer, wire gauze, stand with clamp, pair of tongs, (b) Funnel, burner, clamp and stand, test tube, thermometer, wire gauge, stand with clamp (c) Boiling tube, beaker, thermometer, burner cork with one hole, stand with clamp, wire gauze (d) Round bottom flask, burner, thermometer, wire gauze, stand with clamp, cork with two holes, glass tube. Question 8: What is not a correct precaution to be followed by a student to determine the melting point of ice? (a) Zero mark of the thermometer should remain above the ice surface (b) Keep stirring the mixture and look at the thermometer (c) Crush the ice into small pieces (d) Do not dip the thermometer in crushed ice. Question 9: While heating a liquid, it has to be stirred properly. This is to let: (a) the dust particles not settle at the bottom (b) the liquid get uniform temperature throughout
(c) the liquid get heated quickly (d) the liquid evaporates faster. Question 10: A student set up an apparatus for the determination of boiling point of a sample of water supplied to him in his lab. He recorded the boiling point as 102°C. Assuming that the thermometer is accurate, the error in the determined value of boiling point is due to (a) the water may be containing large amounts of dissolved air (b) the water may not be distilled (c) the bulb of the thermometer is not kept above the water surface (d) The bulb of the thermometer is touching the bottom of the vessel containing water. Question 11: The boiling point of water at the atmospheric pressure is (a) 373 K (b) 273 K (c) 372 K (d) 723 K Question 12: Boiling point of water is (a) 0°C (b) 100°C (c) 40°F (d) 212°C Question 13: In the determination of boiling point of water, it is advised to put the bulb of the thermometer above the water rather than in water, it is to: (a) reduce the error due to atmospheric pressure (b) make sure that boiling point is accurate even when water sample contains non-volatile impurities dissolved (c) reduce the error due to expansions of glass because of heat (d) obtain the boiling point accurately even in a much short time. Question 14: To find the melting point of ice what should be taken in the beaker? (a) Salt + ice (b) Ice cubes (c) Crushed ice (d) Ice cubes & crushed ice Question 15: At 0°C or 273 K, the physical state of water is observed as: (a) solid (b) liquid (c) vapour (d) both solid and liquid Question 16: What is the state of water at 100°C? (a) solid (b) vapour (c) liquid (d) liquid and vapour. Question 17: Water in a container is heated uniformly from 0°C to 100°C. The volume (a) increases continuously (b) decreases continuously (c) decreases up to 4°C and increases further (d) increases up to 4°C and decreases further. Question 18: At room temperature a student sets up an apparatus to determine the melting point of ice. He takes a beaker half filled with crushed ice and dips a mercury thermometer in it. After this he would observe that: (a) mercury in the thermometer keeps on falling till it reads – 1 °C, it remains constant thereafter (b) temperature falls, reaches 0°C and remains constant only as long as both ice and water are
present in it (c) the temperature falls, reaches 0°C and remains constant even after the whole of ice has melted (d) the temperature falls at the starting but starts rising as soon as the ice starts melting. Question 19: When we observe the melting of ice, the melting point of ice is a constant temperature at which (a) both ice and water are present (b) only water is present (c) only ice is present (d) first ice and then only water Question 20: What will be boiling point of water at hill stations? (a) 100° C (b) < 100° C (c) > 100° C (d) Either less than 100° C or more than 100°C. Question 21: When some common salt is added to water, the boiling point of water (a) decreases (b) increases (c) does not change at all (d) depends on the amount of salt. It may increase or decrease. Question 22: When water boils, its temperature (a) remains constant (b) first increases then decreases (c) first decreases then increases (d) keeps on increasing
Questions based on Reporting and Interpretation Skills Question 23: When a thermometer is kept in ice, the reading shows that (a) temperature keeps increasing (b) temperature keeps decreasing (c) temperature increases first and then decreases (d) temperature first decreases and then remain constant at 0°C. Question 24: A thermometer has 20 equal divisions between 90°C and 100°C mark. A student while determining the boiling point of water finds that the mercury thread becomes stationary at the 19th mark above 90°C. He should record the boiling point of water as: (a) 90.19°C (b) 99.5°C (c) 109°C (d) 119°C. Question 25: When water boils, its temperature then (a) decreases (b) increases (c) remains the same (d) first increases then decreases Question 26: In the determination of boiling point of water, correct reading in the thermometer is noted when (a) water starts boiling (b) whole of the water evaporates (c) temperature starts rising (d) temperature becomes constant Question 27: Which experiment set-up is correct for determining the melting point of ice? (a) A (b) B
(c) both A & B (d) none of the above Question 28: When ice is heated continuously, its temperature does not rise because (a) heat is converted into latent heat (b) heat is not used at all (c) heat escape from the system (d) none of these. Question 29: Which of the following statements is right with reference to the melting of ice? (a) At melting point only ice exists (b) At melting point only water exists (c) At melting point both ice and water exist (d) At melting point ice, water and steam exist. Question 30: A thermometer shows 20 divisions between 10°C and 20°C. What is the least count of thermometer? (a) 1 (b) 0.1 (c) 2 (d) 0.5
SCORING KEY WITH EXPLANATION
1. (a) Ice is formed at 0 degree and ice melts at 0 degree. 2. (a) Distilled water is pure and will give the correct readings. 3. (b) Distilled water is pure and will give the correct readings. 4. (c) Boiling point of water is 100 degrees Celsius which is 373 in kelvin (0
degree=273K). 5. (c) On boiling, the water starts bumping in the flask, to prevent it the pumice stones
are added which gives the nucleation site for calm boiling and are inert. 6. (a) Ice just removed from the freezer is dry and the crushed ice is used to find the
melting point of ice. 7. (d) Two holed cork and the glass tube to collect the water vapour is essential. 8. (d) Dip only the bulb of the thermometer in crushed ice. 9. (b) To spread the heat uniformly throughout the water we need to stir continuously. 10. (d) When the bulb of the thermometer touches the container then the temperature
shown by it would be more than 100 degrees Celsius. 11. (a) The boiling point of water is 100 degrees Celsius i.e., 373 K 12. (b) Water boils at 100 degrees Celsius and steam is formed. 13. (a) The boiling point of an element or a substance is the temperature at which the
vapour pressure of the liquid equals the atmospheric pressure surrounding the liquid. Hence the thermometer is placed above the water.
14. (c) Crushed ice is preferred for determining the M.P. of ice. 15. (d) Ice is formed at 0 degree and ice melts at 0 degree. 16. (d) Water boils at 100 degrees and steam is formed. 17. (c) The water molecules are close enough at 4 degrees Celsius and thereafter the
molecules move further apart to increase the volume of water. 18. (b) The temperature read by thermometer will be 0 degree until all the ice is
converted into water, thereafter the temperature may start rising. 19. (a) At 0 degree Celsius both ice and water exists. 20. (b) Boiling point of water changes with altitude because atmospheric pressure
changes with altitude. 21. (b) On adding impurities to water its BP will increase.
22. (a) When water attain its boiling point, the temperature remains the same until all the water is changed into steam.
23. (d) The thermometer will read the temperature of ice that is 0 degree, lower than the room temperature.
24. (b) The least count of thermometer is 0.5 and hence the reading will be 99.5 25. (c) When water attain its boiling point, the temperature remains the same until all the
water is changed into steam. 26. (d) The correct method of recording the B.P. of water is when the water is seen boiling
and the thermometer reading is constant. 27. (b) Crushed ice is preferred for determining the M.P. of ice. 28. (a) When ice at -10 degrees C is heated, its temperature rises until it reaches 0 degrees
C. 29. (c) The melting point of ice is 0 degree Celsius and the freezing point of water is also
the same hence both ice and water exists at this temperature. 30. (d) Least count = range/number of divisions, 10/20=1/2=0.5
SEA(Subject Enrichment Activity)(5M) – Lab activities are considered as SEA for science. The lab
activities given above are to be written in the lab record in the given pattern.
MA(5M):
Task: Individual
learn that matter exists in three different states
understand basic properties of three states of matter.
explain different processes and phenomenon on the basis of properties of different
states.
explain that matter exists in three different states.
explain that matter can be converted from one state to another.
give detailed explanation for different processes on the basis of properties of different
states
Student Worksheet
Q.1. Which of the following changes represent sublimation?
(a) solid liquid
(b) solid gas
(c) liquid gas
(d) gas liquid
8
Chapter 1 - Matter In Our Surroundings Teachers’ Manual On Formative Assessment
Q.2. Gases do not have–
(a) high compressibility
(b) high fluidity
(c) high density
(d) large volume
(b) is a bulk phenomenon
(c) takes place above boiling point
(d) is surface phenomenon
(a) are most ordered
(d) can slip and slide over each other
Q.5. Which of the following pairs will not exhibit diffusion?
(a) hydrogen, oxygen
(b) oxygen, water
(c) salt, sand
(d) sugar, water
Q.6. Which of the following is not a property of solids
(a) fixed shape and volume
(b) interparticle spaces are minimum
(c) Particles can move freely within a limited space
(d) Forces of attraction between the particles are maximum
Q.7. The solid that would sublime on heating is
(a) wax
(a) heating and compression
(b) heating and decompression
(c) cooling and decompression
(d) cooling and compression
9
Teachers’ Manual On Formative Assessment Matter In Our Surroundings - Chapter 1
Q.9. A substance melts at -250
C and boils at 850
C, Which of the following statements about it
is correct?
C
C
C
(d) It can in liquid state or in gaseous state at -850
C
Q.10. Melting points of four solids A, B, C and D are 780
C, 2620
C, 1000
(a) A>C>D>B
(b) B>C>D>A
(c) A>D>C>B
(d) B>D>C>A
Suggestive Remediation:
1. The concepts in which students give wrong answers or are not able to make a fair
judgement need to be taught again.
2. Diffusion is a phenomenon in which particles move on their own and cause intermixing.
Students have a misconception of using the words diffusion and intermixing
interchangeably.
3. Some students might find it difficult to visualise diffusion of sugar in water and also
why salt and sugar do not diffuse. A real activity may be set up to clarify the doubt.
4. Students also have a misconception about the spaces between the particles and their
motion in different states of matter. It should be clarified.
5. Students usually have a misconception about evaporation, boiling and the role of
temperature of bring about these two processes. It may be clarified.
6. It may be difficult for some students to correlate the properties of the three states
of matter and the physical conditions like temperature and pressure, best suited for
bringing about a given change in state. The correlation may be explained.
10
Chapter 1 - Matter In Our Surroundings Teachers’ Manual On Formative Assessment
Matter In Our Surroundings Chapter-1
Assessment technique Diagram based worksheet
Objectives: To enable the students to—
learn that pressure and temperature determine the state of a substance
appreciate that the three states of matter are interconvertible.
understand that with the change in temperature and pressure, the state of the matter
may change.
Three states of matter are interconvertible.
When heat is provided, solid may change to liquid and the process is called fusion or
melting.
Liquid may be converted into solid by solidification.
When heat is provided to the liquid, the kinetic energy may increase to such an extent
that the liquid may change to vapours.
By applying pressure or reducing temperature, vapours may be converted into a
liquid.
A few solids, on heating, are directly converted to vapours and on cooling, vapour is
converted back to solid. The process is called sublimation.
Assessment criterion: one mark for every correct answer.
Student Worksheet
Instructions:
Study the figure given below for inter conversion of states of matter carefully and answer the
questions that follow:
Liquid
d
c
e
f
b
a
Fusion
Sublimation
Solidification
Condensation
Vaporisation
Sublimation
11
Teachers’ Manual On Formative Assessment Matter In Our Surroundings - Chapter 1
Q.1. Name the process marked as a, b, c, d, e, f.
a. _____________________________________________________________________
b. _____________________________________________________________________
c. _____________________________________________________________________
d. _____________________________________________________________________
e. _____________________________________________________________________
f. _____________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Suggestive Remediation
A few students may not understand how state changes with rise in temperature. They may be
helped to understand the change of state on the basis of kinetic energy of particles. Separate
explanation may be given for the process of sublimation.
Matter In Our Surroundings Chapter-1
Assessment technique: Demonstration based worksheet
Objectives: To enable the students to—
understand that particles of matter are continuously moving(and intermixing on their
own by getting into the space between the particles)
understand the phenomena of diffusion
learn that different substances diffuse at different rates
enhance observation skills
Procedure:
The following information may be given to students in the class
12
Chapter 1 - Matter In Our Surroundings Teachers’ Manual On Formative Assessment
particles of matter are moving continuously
particles of matter are intermixing on their own with each other
the intermixing of particles of two types of matter on their own is called diffusion
rate of diffusion depends on the size and mass of the particles
bigger and heavier particles diffuse slower than smaller and lighter ones.
You may then demonstrate activity 1.4 on page 2, of class IX NCERT textbook. For better
observation, take crystals of KMnO4
in the place of honey may be taken.
Assessment parameters: one mark for every correct answer.
Student Worksheet
Time: 10 minutes
Answer the following questions on the basis of observations made during demonstration.
Q1. What change is observed in the two beakers?
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
______________________________________________________________________________
Suggestive Remediation
Particles of matter are very small so the students would not be able to observe the intermixing
of particles. Examples from real life situations may be taken for effective explanation.
13
Teachers’ Manual On Formative Assessment Matter In Our Surroundings - Chapter 1
Matter In Our Surroundings Chapter-1
Assessment Technique Numerical based worksheet
Objectives: To enable the learners to—
Learn that temperature can be measured in two different scales-degrees Celsius and
Kelvin.
Appreciate that measurement in two scales are inter-convertible
Convert the given temperature in one scale in another scale and vice-verse.
Procedure:
The following information may be given to the students in the class:
Temperature can be measured in two different scales - °C and Kelvin (K)
The SI unit of temperature is Kelvin
K =°C + 273
°C = K – 273
Some examples of interconversion may be given to the students.
Student Worksheet
Q.1. Convert the following temperature to the celsius scale.
a. 470 K
14
Chapter 1 - Matter In Our Surroundings Teachers’ Manual On Formative Assessment
c. 298 K
a. 25°C
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
A sample of water was heated from 25°C to 30°C.
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
_____________________________________________________________________
Formula
Calculation
1 mark for formula for inter conversion of temperature on
Celcius and Kelvin scales (1 Mark for formula for calculation
of rise in temperature 1 mark for each calculation)
(1 x 8) 8 mark
Suggestive Remediation
Few Students may not be able to apply the formula correctly. Sufficient practice may be
provided for the same.
Same Students may put the sign of degree with Kelvin. They may be instructed clearly not
to repeat this mistake.
15
Teachers’ Manual On Formative Assessment Matter In Our Surroundings - Chapter 1
Matter In Our Surrounding Chapter-1
Assessment Technique Project Work
Title: To study the effect of temperature and surface area on rate of evaporation of three different
liquids.
Objective: To enable the students to—
Learn that on heating, a liquid can be changed into vapours and the phenomenon is
called evaporation.
Understand that the rate of evaporation of any liquid depends on surface area,
temperature, humidity and speed of the wind.
Enhance observation skills
Task: Group work
The following information may be given to the students.
When a liquid is heated, a small fraction of particles at the surface, having higher
kinetic energy, are able to break away from the forces of attraction of other particles
and escape into air as vapours.
The phenomenon of change of liquid into vapour at any temperature below its boiling
point is called evaporation
(a) Surface area
(b) Temperature
(c) Vapours of the liquid (humidity in case of water) in the surroundings
(d) Speed of wind
(f) Nature of the liquid
You may then ask the students to study the effect of increase in temperature of the liquid
and surface area on the rate of evaporation using three different liquids e.g. Water, Benzene,
alcohol etc.
Assessment Parameters:
Correct procedure : 02 Marks
Correct recording : 02 Marks
Conclusion & result : 01 Marks
Requirement: 6 China dishes of the same of size, stop watch, 10 mL. pipette, measuring cylinder,
thermometer, burner / spirit lamp .
16
Chapter 1 - Matter In Our Surroundings Teachers’ Manual On Formative Assessment
Procedure:
(2) Mark them A1 B1 ; A2 and B2
; A3 and B3
.
(3) Pour 10 mL. of the same liquid in each chinadish of one set .
(4) Heat one china dish of each set (with different liquid) .
(5) Note the volume of the liquid left after every two minutes and record the observation
in the following table:.
A1
B1
A2
B2
A3
B3
Conclusion: ___________________________________________________________________
______________________________________________________________________________
The experiment may be repeated by students in groups to study the other factors.
Suggestive Remediation
The students may find it difficult to observe the changes in the volume of liquids after
regular intervals of time. Repeated adjustments in experiment may help them to observe
desired result
The work may be extended to conduct of experiment on different days/ when humidity in
the air is different and by taking same amount of the liquid in containers of different sizes
to change surface area.