View CLASS 10 SCIENCE PRACTICAL MANUAL 6 ONWARDS flipbook.
1 | SCIENCE SCIENCE EXPERIMENTS CLASS: X
2 | SCIENCE Observation: Sample Colour on pH paper A Orange B Dark blue C Green D Light blue E Green F Pink
3 | SCIENCE EXPERIMENT – 6(A) Aim To determine the pH of the given samples using pH paper or universal indicator. The samples whose pH has to be determined are: Dilute CH3COOH, Dilute NaOH, Salt NaCl , Dilute NaHCO3, Water , Lemon juice Materials required: Six test tubes, Test tube stand, Dilute acid CH3COOH , Dilute base NaOH , Salt NaCl (preparation: dissolve 1 gram salt in 10 mL distilled water) , Water , Lemon juice, Dilute NaHCO3 , Glass rod, Measuring cylinder (10 mL), Standard pH colour chart, pH paper, Glass rod, Dropper, Universal indicator Theory: What is pH? pH is a measure of hydrogen ion concentration to determine the alkalinity or acidity of a solution. • If the pH value of a solution is less than 7 it is an acidic solution • If the pH value of a solution is greater than 7 it is a basic solution • If the pH value of a solution is equal to 7 it is a neutral solution 5. Observe the colour change. Result and Conclusion: Precautions: •Use freshly prepared test sample for the experiment. • The fruit juice sample should also be fresh to get the proper pH values. Glass rod or dropper used for one sample should be washed thoroughly before using it for the other samples
4 | SCIENCE Experimental Setup for Reaction with Zinc metal: . Observation: Experiment Observation Litmus test The blue litmus solution in test tube 1 turns red whereas there is no change in colour observed in the test tube 2 containing red litmus solution. Reaction with Zinc metal Acids such as hydrochloric acid (HCl) liberate hydrogen gas when reacted with active metals such as zinc and burns with a pop sound when burning splinter is got near it. Reaction with Na2CO3 Sodium carbonate and hydrochloric acid react to produce carbon dioxide gas and turns lime water milky. When excess gas is passed the milkiness is disappeared. Reaction: 2HCl(aq) + Zn(s) → ZnCl2(aq) + H2↑ Reaction: Na2CO3(s/aq) + 2HCl(aq) –→ 2NaCl(aq) + CO2↑+ H2O(l) Ca(OH)2(aq) + CO2↑ –→ CaCO3(s) + H2O(l) CaCO3(s) + H2O(l) + CO2(g) –→ Ca(HCO3)2(aq)
5 | SCIENCE EXPERIMENT – 6(B) Aim: To study the properties of acids (dilute HCl) and bases (dilute NaOH) by their reactions with the following: 1. Litmus solution (red/blue) 2. Zinc metal 3. Solid sodium carbonate Materials required: Test tube , Test tube stand , Cork , Test tube holder, Boiling tube , Droppers, Flat bottom flask , Burner , Matchbox , Beaker , Thistle funnel, Litmus paper/solution, Fresh lime water, Glass rod, Dilute HCl, Dilute NaOH, Zinc granules, Solid sodium carbonate Theory: What is acid? Chemical species which donate protons or release H+ions when dissolved in water are called acid. They turn blue litmus solution to red colour. Hydrochloric acid reacts with zinc metal to produce zinc chloride and hydrogen gas. The reaction is given below: Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g) Hydrochloric acid reacts with Na2CO3 to produce carbon dioxide and turns the lime water milky as it forms calcium carbonate. The milkiness formed disappears when more than necessary carbon dioxide is passed through the solution. Result and Conclusion: 1. In the litmus test experiment the blue litmus solution turns red when hydrochloric is added. Therefore, acids such as HCl show acidic character. 2. Hydrochloric acid reacts with active metals such as zinc to form zinc chloride and liberate hydrogen gas. 3. HCl reacts with sodium carbonate to liberate carbon dioxide gas. Therefore, from the above three points we can conclude that HCl (Hydrochloric acid) is acidic in nature. Precautions : • Conduct the experiment in clean test tubes. • HCl is corrosive in nature and should be handled with great care. • Take a small amount of chemicals to perform the experiments. • While shaking the solution and reaction mixture do not spill.
6 | SCIENCE Observation and results: Properties Observation Determination of odour Pungent/vinegar smell Checking its solubility in water Dissolves in water Determining the effect on litmus Blue litmus paper turns red Reaction with sodium bicarbonate A colourless gas is produced which turns the lime water milky
7 | SCIENCE EXPERIMENT - 7 Aim: To study the following properties of acetic acid (ethanoic acid)- 1. Odour (Smell) 2. Solubility in water 3. Effect on litmus 4. Reaction with sodium bicarbonate Materials required: Test tube, Litmus paper, Dropper, Cork fit, Test tube stand, Water, Beaker, Acetic acid, Sodium bicarbonate, Distilled water, Lime water (freshly prepared) Theory: The chemical name of acetic acid is ethanoic acid and has the chemical formula CH3COOH. The COOH group is called the carboxylic group which is responsible for the properties of ethanoic acid. This acid freezes at 16.6° C hence called glacial acetic acid. It smells like vinegar and dissolves in water. It is a weak acid as it dissociates particularly in water. It reacts with alcohol to obtain ester. It reacts with sodium bicarbonate to give carbon dioxide gas. Results: 1. Ethanoic acid or acetic acid or glacial acetic acid smells like vinegar. 2. Glacial acetic acid is water-soluble. 3. Ethanoic acid turns blue litmus paper red. 4. When acetic acid reacts with sodium bicarbonate, carbon dioxide gas is liberated. Precautions: 1.Handle the solution with care. 2. Add a small amount of sodium bicarbonate. 3. Do not inhale the vapours of the chemicals. 4. Lime water should be freshly prepared.
8 | SCIENCE Experimental Setup
9 | SCIENCE EXPERIMENT – 8 Aim To trace the path of the rays of light through a glass prism. Theory What is a prism? A prism is defined as a polyhedron with a triangular base and three rectangular lateral surfaces. It is used as an optical object to study the behaviour of white light when it is passed through it. The light bends at various angles like an angle of incidence, angle of reflection, angle of refraction, and angle of deviation. What is the angle of deviation? The angle of deviation is defined as the angle between the incident ray and the emerging ray. Materials Required A white sheet , Soft board , Thumb pins , 4-6 all pins, Prism , Pencil, Scale, Protractor, Drawing board Observations 1. At surface AB, the light ray enters and bends towards the normal on refraction. 2. At surface AC, the light ray bends away from the normal as it travels from one medium (glass) to the other (air). 3. The angle of deviation is observed. Here, the emergent ray bends at an angle from the direction of the incident ray. Conclusion 1. The incident ray bends towards the normal when it enters the prism and while leaving the prism it bends away from the normal. 2. With the increase in the angle of incidence, the angle of deviation decreases. After attaining the minimum value, it increases with an increase in the angle of incidence. Precautions • For drawing the boundary of the prism, a sharp pencil should be used. • Soft board and pointed pins should be used. • The distance between the pins should be 5cm or more. • The pins should be fixed vertically and should be encircled when they are removed from the board. • The angle of incidence should be between 30° and 60°. • The arrows drawn for incident ray, reflected ray and emergent ray should be proper. • For viewing the col-linearity of all four pins and images, the head should be slightly tilted on either side. While doing this it can appear as if all are moving together.
10 | SCIENCE Observations Metal added Al2(SO4)3 sol. ZnSO4 sol. FeSO4 sol. CuSO4 sol. Aluminium —– Zn is displaced Fe is displaced Cu is displaced Zinc No reaction —– Fe is displaced Cu is displaced Iron No reaction No reaction —– Cu is displaced Copper No reaction No reaction No reaction —– 2Al + 3ZnSO4 → Al2(SO4)3 + 3Zn 2Al + 3FeSO4 → Al2(SO4)3 + 3Fe 2Al + 3CuSO4 → Al2(SO4)3 + 3Cu Zn + Al2(SO4)3 → No reaction Zn + FeSO4 → ZnSO4 + Fe Zn + CuSO4 → ZnSO4 + Cu Fe + CuSO4 → FeSO4 + Cu
11 | SCIENCE EXPERIMENT – 9 Aim a) To observe the action of Zn, Fe, Cu and Al metals on the following salt solutions: ZnSO4 (aq) FeSO4 (aq) CuSO4 (aq) Al2(SO4)3 (aq) b) Arrange Zn, Fe, Cu and Al metals in the decreasing order of reactivity based on the above result. Apparatus and Chemicals : Test tubes , Test tube stand , Distilled water, Four metals (Fe, Cu, Al, and Zn) , FeSO4 solution, CuSO4 solution, Al2(SO4) solution, ZnSO4 solution, Sand paper Principle A more reactive metals displaces a less reactive metal from its salt solution. The reactivity of these four metals is in the order Al > Zn > Fe > Cu. As such aluminium will displace Zinc, iron and copper. Zinc will displaces iron and copper from their solutions. But it will not displaces aluminium from its salt solution. Iron will displace only copper from its salt solution. Copper can’t displace Al, Zn and Fe Inference : The order of reactivity of these four metals is ; Al > Zn > Fe > Cu Precautions • Use only distilled water for the experiment. • Add 1-2 drops of conc. H2SO4 to clear the solutions of metals salts (if needed). • Thoroughly clean the apparatus before the experiment.
12 | SCIENCE Observation and results: Test tube Observation X Forms lather Y White precipitate is formed Results: ● The test tube which is marked X forms foam when mixed with soap solution. ● The test tube which is marked Y does not form foam but forms a white precipitate when mixed with soap solution. Observation and results: Test tube Observation P Oil emulsifies Q No emulsification Results: ● The test tube which is marked P emulsifies due to the presence of soap solution. The test tube which is marked Q does not emulsify due to the presence of soap solution
13 | SCIENCE EXPERIMENT - 10 Aim: The aim of this experiment – Study the comparative cleaning capacity of a sample of soap in soft and hard water. Materials required: 1. Test tube (2) 2. Measuring cylinder 3. Test tube stand Theory: Soap is the potassium or sodium salt of long chain carboxylic acid. The basic structure consists of a long hydrophobic hydrocarbon end and a hydrophilic anionic end. The hydrophobic end is the tail whereas the hydrophilic end is the head. Emulsion in water is formed when the ionic end of the soap molecule is towards the water and the non-ionic end of the soap molecule is towards oil. What is soft water? The water which has no salt in it is called soft water. When soap is used in soft water it generates foam which is a cleansing property and removes dirt particles from clothes. Therefore, this water is suitable for washing. What is hard water? The water which has dissolved salts such as calcium or magnesium in it is called hard water. When soap is used in soft water it does not generate foam. Therefore, this water is unsuitable for washing. Precautions to be taken during the experiment: ● Make a sufficient amount of soap solution so that the same solution is used for soft water as well as hard water. ● Add an equal amount of soap solution to both the test tubes. ● Take equal concentration test tubes. ● Mix the soap solution added to the test tubes in a similar pattern and for an equal period of time. ● Use the same cooking oil in both the test tubes.
14 | SCIENCE Circuit Diagram A. Least count and range of voltmeter and ammeter Voltmeter Ammeter Range Least Count B. Readings of voltmeter and ammeter S.No. Potential difference (V) Current (I) Resistance R = V/I 1. 2. 3. Calculation Mean value of R = ___________ Ω Graph:
15 | SCIENCE EXPERIMENT – 11 Aim To study the dependence of current (I) on the potential difference (V) across a resistor and determine its resistance. Also plot a graph between V and I. Materials Required : Battery eliminator, Ammeter, Voltmeter , Rheostat , One way plug key, Resistor, Connecting wires Theory Ohm’s Law: At constant temperature, the potential difference (V) across a conductor is directly proportional to the current (I) flowing through it. Mathematically, V ∝ I or V = IR or R = V/I Where, R is constant of proportionality and is known as resistance. Factors affecting resistance: • Length of the conductor (R ∝ l) • Cross-section area of the conductor (R ∝ 1/A) • Nature of the material Conclusions 1. For all the three readings, the R-value is the same and constant. 2. The ratio of potential difference V and current I is the resistance of a resistor. 3. With the help of the graph between V and I, Ohm’s law is verified as the plot is a straight line. Precautions 1. Thick copper wires should be used as connecting wires and using sandpaper, their insulation should be removed. 2. The connections should be tight. 3. Voltmeter should be connected in parallel with the resistor. 4. To avoid unnecessary heating in the circuit, the current should be passed for a short time.
16 | SCIENCE Observation Table Resistor used No.of observati ons Voltmet er reading in Volts (V) Ammet er reading in Ampere (I) R=V/I (in Ohm) Mean value of resistan ce (Ohm) R1 (first resistor) a b c R2 (second resistor) a b c 1/Rp=(1/R1)+(1/R2) Parallel combination a
17 | SCIENCE EXPERIMENT – 12(A) Aim To determine the equivalent resistance of two resistors when connected in parallel. Theory If the resistors are connected in parallel along with a battery, then the total current I is calculated as a sum of the separate value of current through each branch. It is given as: I = I1+I2+I3+…. Materials Required 1. A battery 2. A plug key 3. Connecting wires 4. An ammeter 5. A voltmeter 6. Rheostat 7. A piece of sandpaper 8. Two resistors of different values Result The calculated value of 1/Rp The experimental value of 1/Rp The equivalent resistance Rp is less than the individual resistance. Precautions 1. The connecting wires used should be thick copper wire and using sandpaper, the insulation at the end of the wires should be removed. 2. The connections should be tight to avoid introducing external resistance. 3. To make connections, the circuit diagram should be referred to. 4. To make the current entry from the positive terminal and exit from the negative terminal, the ammeter should be connected in series.
18 | SCIENCE Circuit Diagram Observation Table Resistor used No.of observati ons Voltmet er reading in Volts (V) Ammet er reading in Ampere (I) R=V/I (in Ohm) Mean value of resistance (Ohm) R1 (first resistor) a b c R2 (second resistor) a b c 1/Rp=(1/R1)+(1/R2) Parallel combination a
19 | SCIENCE EXPERIMENT – 12(B) Aim To determine the equivalent resistance of two resistors when connected in series. Theory The resistance can be increased or decreased depending on the combination and connections in a circuit. The difference between the series and parallel circuit is based on the arrangement of the resistors. Resistors are said to be connected in series if their ends are joined. The potential difference across each resistor would be different, but the current would be the same. If two resistors are connected in series, then; Resistance, R = R1+R2 , Current, I = constant Potential difference, V = V1+V2 On applying Ohm’s law, we get, V1 = IR1 V2 = IR2 V = V1+V2 V = I(R1+R2) ∴ R = R1+R2 Materials Required : Two resistors of different values , A battery of 6 volts , Ammeter , Plug key, Connecting wires, A piece of sandpaper, Voltmeter , Rheostat Rs=R1+R2 (series combination) Result The calculated value of Rs The experimental value of Rs Hence, it is verified that Rs=R1+R2. Precautions 1. Voltmeter and resistor should always be in parallel. 2. The least count of voltmeter and ammeter should be calculated properly. 3. Connections should be as per the experimental setup. 4. When no current flows through the ammeter and voltmeter, the pointers should be at zero.
20 | SCIENCE Diagram Observation ● The bean seed resembles the shape of a kidney. It has a convex and a concave side ● A scar known as the hilum is observed on the slightly darker side of the concave side ● A tiny pore known as the micropyle is located just adjacent to the hilum ● The seed is enclosed by a seed coat ● The embryo possesses two distinct and large cotyledons that resemble the shape of a kidney and are white in color ● Lateral attachment of the cotyledons to the curved embryonal axis is observed ● Radicle is examined. It is the rod-shaped and lightly protrusive lower end of the embryonal axis that is found placed towards the micropylar end. ● The upper end of the embryonal axis exhibits the plumule ● Hypocotyl is observed which is a section of the embryo axis found in between the radicle and adjunct of cotyledon leaves ● The epicotyl is also observed which is the section of the embryo axis between the adjunct of cotyledon leaves and plumule
21 | SCIENCE EXPERIMENT - 13 Aim To identify the different parts of an embryo of a dicot seed Principle/Theory The process of fertilization in plants leads to the formation of fruits which forms the ripened ovary. The seed can be one or many which form the mature ovule. What does a seed consist of? A seed consists of the following parts: ● Hilum – It is a scar that is located on the seed coat, associated with the stalk of the plant ● Seed coat – Forms the exterior covering of the plant, supplying with nourishment and protection to the seed inside ● Endosperm – It is the tissue containing nutrients for the growth of the embryo ● Embryo – Several divisions of the zygote gives rise to this structure. Material Required ● Seeds of red kidney bean/gram ● Forceps ● Magnifying glass ● Cloth ● Petri dish ● Water Conclusion Three principle parts of the embryo of dicot seeds are observed, they are: ● Cotyledons ● Plumule ● Radicle Precautions ● Care needs to be taken while dissecting the seed as it may damage the seed ● The cloth that is used to wrap the seeds needs to be moist
22 | SCIENCE Diagram Observation a) Binary fission in Amoeba ● Initially, the pseudopodia are retrieved. The body of amoeba is coiled and becomes round ● Amitosis is observed, the division of the nucleus takes places which are followed by splitting of cytoplasm ● At the point of fission in the body of the amoeba, a constriction starts to develop. ● The constriction or furrow turns deeper resulting in the formation of two daughter cells (b) Budding in yeast ● Protuberance or a tiny outgrowth is observed on the parent cell ● Division of the nucleus is observed which is later seen in the bud ● Repetitive budding leads to the formation of a chain of cells
23 | SCIENCE EXPERIMENT - 14 Aim To study about (a) Binary Fission in amoeba and (b) Budding in yeast with the help of prepared slides Principle/Theory Budding and binary fission are types of asexual reproduction observed in lower organisms such as bacteria, unicellular protozoans and some other entities. What is binary fission? In this type of reproduction, the parent cell divides or is split into two daughter cells through mitosis wherein each daughter cell develops into an adult. Amitosis is the division of the nucleus. Define budding? It is a kind of asexual reproduction wherein a new organism develops from a bud or an outgrowth due to the process of cell division at a particular site. Material Required ● Compound microscope ● Permanent slides of budding in yeast and binary fission in amoeba Conclusions The prepared slides display asexual reproduction. One individual is involved to produce a new offspring of its own kind. Precautions ● Slides need to be aligned and focused accurately ● Sketch out your observation that is observed under a microscope ● The slides first need to be examined under a low-power magnification of the compound microscope and then under high-power magnification.