81-105 - Delhi

Class X
EXPERIMENT No: 10
AIM: To show experimentally that carbon dioxide is given out during respiration.
Materials Required :
Germinating seed, conical flask, small test tube containing KOH, small thread, bent capillary
tube, beaker and cork.
Procedure :
1. Take some germinating seeds of moong dal in a conical flask.
2. Place a small test tube containing KOH solution in hanging position in the flask.
3. Fix a bent capillary tube with one end in conical flask and other end in the beaker
containing colored water.
4. Keep the set up for about two hours and observe change in water level in capillary tube.
Observation :
Germinating seeds
1. Note the water level position at the start of the experiment.
2. Record the rise of water level in capillary tube.
3. Record water level change in record book.
Result and Inference :
1. Germinating seeds absorb oxygen of conical flask and release CO . 2
2. Released CO is absorbed by KOH
2
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3. Water rise up in capillary to fill space created by gas.
4. Germinating seeds give out CO during respiration.
2
Precaution :
1. Mouth of conical flask should be air tight with cork.
2. Handle KOH carefully since it is corrosive.
3. Seeds should be germinated and respiring.
4. Hang small test tube with the help of a fine thread.
5. Colored water gives better observation.
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Class X
EXPERIMENT No: 1
AIM: To sturdy the following properties of Acetic Acid ethanoic acid:
i. Odour
ii.
iii.
iv.
Solubility in water
Effect on litmus (blue)
Effect on litmus (red)
Materials Required : 5% acid (Acetic acid), sodium hydrogen carbonate (solid), blue, & red
litmus paper strips, distilled water, two beaker (100 ml), Four test tubes with stand, a dropper, lime
water & passing tube.
Procedure : Study the pretties of acetic acid (according to the following table.
Sr. No. Experiment ObservationInference
1. Odour : It smells like Acetic acid has vinegar
Smell the sample of vinegar
acetic acid carefully
taken in a test tube.
2. Solubility :
a. Add 1 ml of the given Acetic acid dissolves Acetic acid is soluble in
sample of acetic acid in in water in water
2 ml of water.
b. Add more acetic acid in It also dissolves Acetic acid is soluble in
the above test tube
water in all proportions.
3. Effect on litmus :
With the help of dropper Only blue litmus Acetic acid is acidic in
of acetic acid on paper turn red. nature.
(i) blue and (ii) red litmus
paper
Red litmus gives no
colour change
4. Reaction with sodium
hydrogen Carbonate :
a. Take 1 ml of the acetic A brisk effervescence Acetic acid produce CO2
acid and add to it a pinch produces with a gas with sodium hydrogen
of sodium hydrogen. clourless gas carbonate.
Carbonate
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. Pass CO gas in Lime Lime water turns Milky colour of lime water is
2
water. milky. insoluble in calcium
carbonate.
Result :
Acetic acid (ethanoicatid) has following properties :
a. It has vemigar like smell.
b. It is highly soluble in water
c. It turns blue litmus to red.
d. It produces CO gas with sodium hydrogen.
2
Precautions :
1. Handle ethanoic acid very car fully.
2. Small mount of sodium hydrogen carbonate should be added in smell mouth of acetic
acid to contemp intensity of CO evolution.
2
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Class X
EXPERIMENT No: 2
AIM: To study the soaponification reaction of preparation jof soap.
Materials Required : Vegetableoil (25 ml) Suchas castor oil or coconut oil, sodium hydroxide,
common (about 10g), distilled water, two beakers (250ml capacity), two test tubes, measuring
cylinders (50ml salt), a glass rood, a knife.
Procedure :
1. Place about 25 ml castor oil coconut oil in a beaker of 25 ml.
2. Make 50 ml 20% solution of sodium hydroxide in distilled water.
3. Pour 30 ml of above prepared solution of sodium hydroxide in 25 ml of oil taken above
in beaker in the form of thin stream and stir the mixture.
4. The above mixture of beaker becomes viscous and thick, this is a soap.
5. Dissolve 10 g sodium chloride in about 15 ml of water. Add this solution in the soap
formed above with constant stirring till the mixture cools & become solid.
6. Leave it for a day till the mixture and cut it into desired shapes and sizes.
7. Remove the soap from the beaker and cut it into desired shapes and sizes.
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Precautions :
1. Take care in use of solid sodium hydroxide as it is corrosive and cause seveee burn
skin.
2. Stir the mixture carefully so that it does not spill out.
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Class X
EXPERIMENT No: 3
AIM: To sturdy the comparative cleansing capacity of a sample of soap in soft and hard water.
Materials Required : : Distilled water (soft water), under ground water (hard water, soap cake,
digital balance, two beakers (100 ml), two glass rods, two test tube with test tube stand. a
measuring scale & measaring cylinder (50 ml).
Procedure :
1. Label the two beakers A and B.
2. Take 20 ml of distilled water in beaker A and put 50 m l of hard water in B.
3. Weigh 1 g of soap and put it in each beaker.
4. Stir the content of both beakers with separate glass rods.
5. Take the two test tubes and place them in a test tube stand and label soap them I and II.
6. Pour 3 ml of above prepared soap solution of beaker A and B in the two textures places
in the stand.
7. Take in the test tube I and II and shake them ten times by placing them on it's mouth.
8. Foam or lather will form by shaking the test tubes (two minutes each.)
9. Measure the length of the lather produced immediately by using measuring cylinder
and record observations:
Observations :
a. Volume of soft and hard water taken in beaker A and B = ................... ml.
b. Mass of the soap put in each beaker = .................. g.
c. Volume of the soap soltuon taken in test tube and II = ................. ml.
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S.
No.
Water
take
Initial length (cm)
Test tube reading
Final length (cm)
Form/lather
Produced (cm)
1. Soft
Water
2.
Hard
Water
1. A rich lather is produced in test tube I containing soft water.
2. A sticky scum in produced in test tube II containing hard water.
Result : For cleaning purpose the foam or lather needs to be produced should be more, thus soft
water is suitable for washing.
Precautions :
1. Always use distilled water as soft water.
2. Use same soap sample for both water.
3. Hard water if not available can be prepared by dissolving 5 g of calcium chloride or
magnesium chloride in the foam produced.
4. Measure the length of the foam produced immediately.
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Class X
EXPERIMENT No: 4 (i)
AIM: To determine the focal length of a concave mirror by obtaining image of distant object.
Apparatus / Material Required :
A concave mirror, a mirror holder or stand, a small screen (hard sheet of whit
paper/cardboard) fixed to stand, scale, notebook, pencil.
Procedure :
1. Fix the concave mirror on the mirror holder or stand and place it on the table near an
open window of the laboratory.
2. Locate a distant tree / building from the open window (if an open window is not available
then obtain the image of window itself of the screen).
3. Place the screen in front of the mirror.
4. Adjust the position of the concave mirror and the screen so that a sharp, inverted and
diminished image of a distant object is formed on the screen.
5. Note the position of the screen and concave mirror stand with the help of meter scale.
6. Find the distance between the centre of concave mirror and the screen. This distance is
equal to the focal length of concave mirror Record the focal length.
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7. Repeat the experiment a few times by changing the position of the mirror stand and
note the corresponding change position of the screen.
8. Calculate the mean value of the focal length.
Observation and Calculation:
S.No. Position of the Position of the Focal length of the
concave mirror white screen (Q) conceave mirror (Q-P)
(P) (in cm) (in cm) (in cm)
1 _______ _______ f1 = --------
2 _______ _______ f2 = ---------
3 _______ _______ f3 = ----------
4 _______ _______ f4 = -----------
Precautions :
Mean value of focal length of concave mirror f
= f1+f2+f3+f4
4
= --------- cms
1. The concave mirror should be fixed in the vertical plane.
2. The base of the concave mirror stand and the screen should be parallel to the meter
scale.
3. Record the position of screen only when a well defined, inverted and diminished image
of the distant object is formed on the screen.
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Class X
EXPERIMENT No: 4 (ii)
AIM: To determine the focal length of a convex lens by obtaining an image of a distant object.
Apparatus/Material Required :
A convex lens, convex lens stand, a small screen (hard sheet of white paper/cardboard) fixed
to a stand, a measuring scale.
Procedure :
1. Fix the comex lens on the lens holder or stand and place it place it on the table near an
open window of the laboratory.
2. Locate a distant tree/buliding from the open glass window (if an open window is not
available then obtain the image of the window itself on the screen.
3. Place the screen behind the convex lens.
4. Adjust the position of the convex lens and the screen so that a sharp, inverted and
diminished image of a distant object is formed clearly on the screen.
5. Note the positions of the screen and the convex lens stand with the help of measuring
scale.
6. Find the distance between the optical centre of the lens and the screen. This distance is
equal to the focal length of the convex lens. Record the the focal length.
7. Repeat the experiment a few times by changing the positions of the convex lens stand
and note the corresponding changed position of the screen.
8. Calculate the mean value of the focal length.
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Observation and Calculation:
S.No. Position of the Position of the Focal length of the
convex lens white screen (Q) conceave mirror (Q-P)
(P) (in cm) (in cm) (in cm)
1 _______ _______ f1 = --------
2 _______ _______ f2 = ---------
3 _______ _______ f3 = ----------
4 _______ _______ f4 = -----------
Mean value of focal length of concave mirror f
= f1+f2+f3+f4
4
= --------- cm
Q
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Precautions :
1. Fix the convex lens vertically in the lens holder.
2. The base of the lens stand and white screen should be in line with the measuring scale.
3. Record the position of the lens and screen only when a well defined sharp image is
formed.
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Class X
EXPERIMENT No: 5
AIM: To trace the path of ray of light, passing through a rectangular glass slab, for different angles
of incidence and to measure the angle of incidence, angle of refraction, angle of emergence and
interpret the result.
Apparatus / Material Required :
Glass slab (rectangular) A drawing board, all pins, drawing paper/white sheet paper drawing
pins, protector, scale and pencil.
Procedure :
1. Fix a plain sheet of paper on a drawing board with help of drawing pins.
2. Place a rectangular glass slab in the middle of the paper and draw its boundary with a
sharp pencil.
3. Fix two pins (P and Q) vertically along a straight live on one side of the glass slab.
4. Now look through the glass slab form the other side and fix two pins (R and S), so that
those pins and the image of the pins P and Q are in a straight line (when seen through
the glass slab).
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5. Remove the glass slab and all the pins one by one and draw small circles around the
pin pints.
6. Join the points P and Q and extend the line to meet the face AB of the slab at E.
7. Similarly, extend the line obtained by joining points R and S to meet the other face DC of
the slab at pt F.
8. Join points E and F.
9. Draw perpendiculars to the two faces of the slab at point E and point F.
10. Measure (i) the angle of incidence (ii) the angle of refraction (iii) and the angle of
emergence and record and observation.
11. Repeat th experiment for different angles of incidence and determine the
corresponding angle of refraction emergence.
Observation and Calculation:
No. Angle of Angle of angle of Difference betwee the
incidence refrection emergence angle of incidence and
(i) (ii) (iii) angle of emergence (i-e)
1
2
3
4
Conclusion :
1. Angle of incidence = Angle of emergence
2. Incident ray is parallel to the emergent ray
3. Angle of refraction is less than angle of incidence
4. With the increase in angle of incidence, the angle of refraction increases.
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Precautions :
1. The drawing board should be of some soft wood.
2. The pins should be fixed in an upright position.
3. While fixing pins the bases of all the pins should be in the same straight line.
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Class X
EXPERIMENT No: 6
AIM: To study (a) binary fission in Amoeba and (b) budding in yeast with the help of prepared
slides.
Materials Required :
Compound microscope, permanent slides of binary fission in Amoeba and budding in yeast,
charts of binary fission and budding.
Procedure :
1. Focus the slide of binary fission of Amoeba under low power of compound microscope.
2. After observing under low power change to high power of magnification.
3. Observe various stages of cell division in binary fission of Amoeba.
4. Draw diagrams of different stages of binary fission in Amoeba.
Binary fission in Amoeba
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5. Focus the slide of budding in Yeast under low power of compound microscope.
6. After observing under low power, change to high power of magnification.
7. Observe various stages of cell division in budding in Yeast especially chain of buds.
8. Draw diagrams of different stages of budding of budding in Yeast.
Budding in Yeast
Observation :
1. Binary fission in Amoeba shows division of nucleus by stretching.
2. Nucleus breaks into two nuclei slowly and cytoplasm also divides (cytokinesis).
3. Two small daughter cells (Amoebae) are formed at the end.
4. Budding in Yeast shows many cells attached with each other forming a branched chain.
5. Nucleus starts dividing first by stretching and followed by cytokinesis.
6. Daughter cells originate as small buds of parent cell and grow very fast.
7. Daughter cells remain attached with parent cells and separate later on.
Precautions :
1. Keep microscope in box when not in use.
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2. Clean the stage of microscope before and after use
3. Do not tilt the microscope. Microscope should be held vertical.
4. Slide should be firmly clipped on the stage.
5. First observe under low power of microscope and then change to high power lens.
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Class X
EXPERIMENT No: 7
AIM: To trace the path of rays of light passing through the prism.
APPARATUS/MATERIALS REQUIRED: Drawing board, sheet of white paper, glass prism, pins,
scale, protractor, cello tape
PROCEDURE:
1. Take a white sheet of paper and fix it on the drawing board with cello tape or pins.
2. Draw the outline of prism with the sharp pencil as shown then remove the prism.
3. Choose the suitable point X which acts as a point of incidence roughly in the middle of
AB as shown in the figure. Draw normal N to this point.
1
4. Draw a line making angle 30 degrees with the normal. This line will form the incident ray
for angle of incidence 30 degrees.
5 Properly place the prism within the outline ABC.
6. Place two pins P and Q at least 6 cm apart on the incident ray line and view their images
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with one eye closed from the side AC of the prism. Fix another two pins R and S on the
paper such that the tips of these pins and images of the incident ray pins (P and Q) all lie
in the same straight line.
7. Remove the pins and prism. Encircle the pin pricks with a sharp pencil.
8. Join R and S and extend it backward to point Y on AC. Draw a normal N as shown in the
2
diagram.
9. Join XY, which shows the path of light ray inside the prism.
10. Now PQXYRS shows the path of the rays of light passing through the prism.
11. Repeat steps 2 to 10 for other angles of the incidence.
OBSERVATIONS:
From the diagram it is clear that as the ray moves from air ( optically rarer medium ) to glass
(optically denser medium ) it bend towards the normal. And when it moves from glass( optically
denser medium ) to air( optically rarer medium ) it bends away from the normal.
RESULT :
PQXYRS represents the path of light ray through the prism as shown in the diagram.
PRECAUTIONS :
1. The same prism should be used for all observations.
2. Prism should be placed properly inside the drawn marking.
3. The angle of incidence should be taken between 30 degrees to 60 degrees.
4. The separation between the pins should not be less than 6 cm.
5. The pins should be fixed vertically and firmly.
6. The points of incidence should be taken approximately in the middle portion of the
prism.
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Class X
EXPERIMENT No: 8
Aim:- To find the image distance for varying object distances in case of a convex lens and draw
corresponding ray diagrams to show the nature of image formed.
Material and Apparatus required:- Convex lens preferably of focal length 15 cm, candle with
stand, lens holder, a screen with stand, matchbox, meter scale.
Principle:- The nature and position of the image form by convex lens depends upon the position of
the object with respect to convex lens. The image may be real or virtual. For real image, the object
should be placed on the focus or beyond the focus and for virtual image, object should be between
optical centre O and focus F.
Position of
the object
Position of
the image
Size and nature
of the image
Ray-diagram
An infinity at focus F 2
Highly diminished, real and inverted
Beyond 2F 1
between F and 2F
2 2
Diminished, real and inverted
At 2F 1
at 2F 1
Same size real and inverted
Procedure:-
1. Obtain an approximate value of the focal length of the convex lens by focusing the image
of a distant object.
2. Fix a meter scale on the table with a cello tape.
3. Fix lens in a lens holder and place it in the middle the meter scale, such that its principal
axis is parallel to the meter scale.
4. Mount a candle vertically on a candle stand, light it with a matchbox and place it on the left
hand side of the lens. Adjust the height of the candle or the lens such that the tip of the
lighted candle lies or the principle axis of the lens.
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5. Place a vertically mounted card board pasted with graph paper (Screen) on the right side
of the lens. Adjust its height such that the entire image can be taken on the screen.
6. Make adjustment to get a sharp image of lighted candle on the screen, by keeping the
lighted candle at (1) far away from lens (at infinity) (2) beyond 2F (3) at 2F(4) bet 2F and F.
Take at least three observations.
7. When a burning candle is kept at focus, It is not possible to obtain a sharp image at any
position of the cardboard.
Observations :-
Rough focal length of the lens = ………………….…cm
S. No. Position of lens (cm) Position of candle (cm) Position of the image on
the screen (cm)
Nature of image
Result:-
1. As the object moves towards the focus of the lens the size of the image increases and it
moves away from the focus.
2. When object is brought too close to the lens, the image on the other side is not seen.
Precautions:-
1. Perform the experiment at a shaded place.
2. For obtaining the rough focal length of the lens any distant object can be considered either
a tree or sun. If focusing the sun, then not look the image directly, it may hurt the eyes.
3. The aperture of the lens should be small.
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Class X
EXPERIMENT No:9
Aim:- To study homology and analogy with the help of preserved/available specimens of either
animals or plants.
Materials Required : Specimen of turnip root, water melon fruit, bougainvillea shoot with thorn,
cucurbit shoot with tendril, Figures of human hand and wing of bat and photographs of bird wing
and butterfly wing.
Procedure : Take parts of plant and animal objects in terms of Homologous and Analogous
organs as follows-
Homologous organs : Bougainvillea shoot cucurbita shoot
Human hand and wings of bat
Analogous organs : Turnip root and water melon fruit
Observations :
Bird wing and butterfly wing
1. Look for the point of origin of thorns in bougainvillea and
tendril of cucurbit.
Compare that both structures are stem.
Feel the point and the hardness of the thorn.
Tendril
Thorn
What function does it perform?
Look the shape and tenderness of tendril.
What function does it perform?
Bougainvillea thorn & Cucurbit tendril
2. Look the basic skeletal structure of human hand and
bones of the bat wing.
Compare the internal skeletal structure of wings of
boot.
How does hand help holding objects?
How does wing help fly in the air?
Human hand & Wing of Bat
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3. Look the shape and structure of root of turnip and fruit of water
melon.
Compare the food storing part in turnip and water melon.
Identify that food eating part of turnip is root and food eating
part water melon is fruit.
4. Look the basic structure of wing of bird and wing of butterfly.
Compare the fine structural details of wings of bird and
butterfly.
Turnip root & Watermelon fruit
Observe different types of feathers found on
the wing of bird.
Try to identify the scales present on the wing
of butterfly.
Precaution :
Wing and feather of bird & Butterfly wing
1. Be careful while touching thorn of bougainvillea.
2. No damage should be done to either bird or butterfly.
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