» Class X Model Test Paper : CBSE Sample Question Papers

Section - A

1. Relate refractive index with the speed of light in the medium, 1
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2. Name the elements other than carbon that constitute carbohydrates. 1
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3. What is Faraday’s constant ? 1
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4. What are the units of rate of reaction. 1
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5. Give IUPAC name of H-C-H 1
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6. What are solar concentrators ? Give the usual shape of such concentrators. 2
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7. If an object is at 10 cm from a convex lens of focal length 15 cm, find (i) position {ii) nature of image formed. 2
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8. Name two places of one country where fields of natural gas are found. Why is it called a clean fuel ? Give two reasons. 2
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9. When two lenses of focal length 20 cm and - 30 cm are placed in contact. Find the equivalent. (i) Focal length (ii) Power 2
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10. Calculate the pH of the solution when hydrogen ion concentration is lxl0 ^-7 M. State whether the solution is acidic, basic or neutral.

OR
The pH of solution is 4. Calculate hydrogen ion concentration. State the solution is acidic, basic or neutral. 2
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11. A 60 W, 220 V bulb and a 40 W, 220 V bulb are used with a supply of 220 V in series. Find the (*) Net power consumed (it) Identify the brighter of the two bulbs.
OR
A 60 W, 220 V bulb and a 25 W, 220 V bulb are to be connected to a 220 V supply. How will you connect them to get (/) maximum potential in each, («) current through each bulb. 3
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12. Write chemical equations to show what happens when ;
(i) Concentrated HNO₃ is poured over sulphur powder. {ii) Na₂CO₃.10H₂O crystals are exposed to air {Hi) Manganese dioxide is heated with aluminium. 3
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13. Draw a labelled diagram of an A. C. generator. Write the basic principle underlining its functioning.3
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14. How does pyrcx glass differ from soda glass ? Give composition of lead crystal glass. 3
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15. Explain the role of ciliary muscles, cornea and aqueous humour in helping the eye in its ability of accommodation. 3
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Section - A

1. Name the largest component of biogas, 1
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2. Why do we use convex mirror for rear-view mirrors in automobiles ? 1
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3. Name the major metal used for making bodies of aircraft. 1
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4. What is a fuse wire ? Name its constituent materials. 1
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5. Give two characters of energy sources. 1
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6. Name the model that was proposed to explore fission and give one example of fission reaction. 2
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7. Draw a labelled diagram of apparatus for getting wood gas from wood in the laboratory. What name is given to the solid residue obtained? 2
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8. Explain how does concentration affect the rate of reaction ?

OR
State two important properties of washing soda. 2
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9. If a 40 W bulb and a 100 W bulb are operated for 4 hours per day in a month of 30 days. Find the energy consumed at 200 volts of supply potential ? 2
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10. Write IUPAC name of the following ;
(i) CH₃COCH₃, (ii) CH₃COOC2H5. 2
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11. Point out three differences between nuclear reactions and chemical reactions. 3
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12. An organic compound ‘X1 is an essential constituent of wine and beer. X is responsible for the intoxication caused by these drinks. Oxidation of ‘X’ yields an organic acid and ‘Y’ is present in vinegar. Name the compounds X and Y and write their structural formula. 3
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13. What does the Big Bang theory say about the origin of universe ? 3
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14. Determine the pH of the acidic solution formed when 0.02 mol of HC1 is added to enough water to make the final volume 2.0 L.

OR
The pH of a solution changes from 5 to 4. How many times do you expect a change in hydrogen ion concentration. 3
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15. Draw a neat diagram of an astronomical telescope and write the nature of image formed. Write the relation for magnification and the length of telescope under normal adjustment. 3
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Section - A

1. Name the mirror which always forms a virtual image ?
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2. How is slurry left over after generation of biogas in gobar gas plant used ?
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3. Write a condition necessary for current flow.
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4. Define rate of reaction.
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5. How much solar energy is incident on India’s surface (on an average) ?
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6. Which one of the metals in the following group are : (a) most reactive and (b) least reactive Au, Na, Cu, Ca.
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7. How do we see colours ?
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8. Define ‘combustion’. Write the conditions necessary for combustion to take place.
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9. What is energy crisis ? How do we overcome the same ?

OR
What are the advantages and drawbacks in the use of wind energy ?
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10. When two equal resistors are placed in parallel, the equivalent resistance is 5 Q. When they are placed in series, what will be the equivalent resistance ?
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11. State two reasons for counting sulphur among the non-metals. Which properties of sulphur make it possible to bring sulphur from deep mine to the surface of the Earth by the Frasch process and to purify it by sublimation of liquid sulphur ?
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12. What are Geostationary satellites ? In what way they are useful to mankind ?
OR
Explain why nuclear fusion is better than nuclear fission ?
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13. The heat produced on complete combustion of 10 g of fuel could raise the temperature of 2 Kg of water from 20° to 70°C. Calculate the calorific value of the fuel, if the specific heat of water is 4.2 J/g °C.

OR
How much energy will 1 Kg mass of wood yield on complete combustion if its calorific value is 15 kJ/g.
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14. Draw a neat diagram of a compound microscope and explain the nature of image formed. Also write the relation for magnification.
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15. What are magnetic field lines ? List four characters of these lines.
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1. The reaction of a metal ‘X’ with Fe₂ O₃ is highly exothermic and is used to join railway tracks. Identify the metal ‘X’ and write the chemical equation of its reaction with Fe₂ O₃.
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2. Name the metals present in solder.
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3. Doctors use a paste of a white substance in water to keep the fractured bone fixed in its place. Identify the substance and write its chemical formula.
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4. (a) Write an expression of the law of chemical equilibrium for the following hypothetical reaction:

½ X+ 3Y ——-> 2Z

(b) What does the magnitude of equilibrium constant (K) indicate?
© For the reaction

N₂ (g) + 3H₂ (g) ——–> 2N H₃ (g)

express the rate of reaction in terms of :-
▲[N₂] ▲[H₂] ▲ [NH₃]
——, -,—— and ————
▲ t ▲ t ▲ t
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5. How is soda glass prepared? What is the major disadvantage of using this glass?
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6. Name the process that is used for the concentration of sulphide ores. Briefly describe this process.
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7. (a) What are aldehydes and ketones? Name the functional group present in these compounds.
(b) Write the names of two reagents which can be used to distinguish between methanal and propanone.
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8. (a) Write two tests to demonstrate that ethanoic acid (CH₃COOH) is acidic in nature.
(b) Explain why are detergents more effective cleansing agents than soaps in hard water.
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9. (a) Ammonia is manufactured from N₂ and H₂ by Haber process. State the
(i) Temperature, (ii) pressure, and (iii) the catalyst used in the process.
(b) What would you observe when ammonium hydroxide is added slowly to copper (II) sulphate solution until it is in excess. Write the chemical reactions that take place.
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10. (a) The following flow chart represents the extraction of iron;

Iron Ore — Slag

Coke ——-
——-> Blast furnace ——>
A ——-
Iron
B —-

(i) Give the name of the iron ore.
(ii) Give the names of the substances A and B.
(iii) Write down the molecular formula of the slag formed.
(iv) What is the main impurity present in iron obtained from the blastfurnace.
(v) Name the chemical process that is used to obtain iron from iron ore.
(b) During the extraction of metals from their ores, the sulphide ores are roasted whereas the carbonate ores are calcined to obtain the oxide of the metal.
(i) Write an equation for the roasting of the zinc ore.
(ii) Write an equation for the calcination of the zinc ore.

Or

(a) The electronic configuration of an element ‘X’ is 2, 8, 6. It occurs in nature both in the combined state as well as in the free state. This element is mined by Frasch process. Answer the following questions.
(i) What is the name of the element ‘X’?
(ii) How many valencies are exhibited by this element? Write those valencies.
(iii) On which property of element ‘X’, the Frasch process is based?
(b) Describe briefly with the help of a labelled diagram the extraction of’X’ by Frasch process.
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1. What is the chemical name of baking soda? Write its formula.
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2. The pH values of equimolar solutions of three acids A, B and C are 2.5, 6.5 and 4.2 respectively. Arrange the acids in order of increasing hydrogen ions concentration.
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3. A statue made of bronze was kept in a museum. After some time it was found that the statue had lost its lustre due to the formation of a greenish layer on its surface. Name the phenomenon responsible for this happening. What is the name of the greenish substance?
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4. When acidified hydrogen peroxide is added to a solution of KI, iodine is liberated according to the following equation:

H₂ O₂ + 2 KI + H₂ SO₄ ——–> 2H₂ O + I₂ + K₂ SO₄

It was found that the concentration of iodine increases from 0 to 8.60 x 10^-6 mol L^-1 in 20 seconds. Calculate the rate of reaction during this time interval.
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5. What do you mean by quenching and annealing of steel?
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6. (a) Write the reactions that take place during the manufacture of sulphuric acid by contact process.
(b) What would you observe when cone. H₂ SO₄ is added to sugar? Explain your observation.
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7. What are polyesters and polyamides? Write an equation for the formation of these polymers.
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8. (a) What is denatured alcohol?
(b) Write chemical equations of the reaction of propanone with (i) sodium borohydride. (ii) alkaline potassium permanganate.
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9. Write an equation for the reaction of
(a) iron with steam.
(b) calcium with water.
© sodium with hydrogen.
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(a) A polymer has the following structure.

—CH₂ —— CH ——- CH₂ ——– CH —– CH₂ — – CH——
I I I
CH₃ CH3 CH₃

(i) Write the name of the monomer of the above polymer. (ii) Is it an addition polymer or a condensation polymer?
(b) Which type of reaction occurs when soap is formed from fats.
(b) Why do the branched chain detergents cause pollution of rivers and water bodies?
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10. Name the chief ore of aluminium. With the help of a labelled diagram and necessary chemical equations, explain how aluminium is extracted from its ore. What is the function of adding cryolite in this process?
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1. State whether an aqueous solution of washing soda is acidic or alkaline. How will you prove it?
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2. Give an example of a non-metal which
(a) has a shiny appearance just like metals,
(b) conducts electricity.
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3. Why are metals reducing agents whereas non-metals are oxidising agents?
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4. What is meant by the term metallurgy? Name its three steps.
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5. A sanitary worker uses a white substance having a strong smell of chlorine to clean a water tank. Identify the substance. How is it prepared? Write the equation of the chemical reaction for its preparation.
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6. (a) Explain the difference between average reaction rate and instantaneous reaction rate.
(b) What is the effect of temperature on the
(a) rate of a reaction.
(b) concentration of product(s) at equilibrium of an endothermic reaction carried out in a closed container?
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7. What are soaps and detergents? Explain the mechanism of the cleansing action of soaps.
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8. Write an equation for the reaction when
(a) sodium acetate is heated with soda-lime.
(b) ethanol reacts with ethanoic acid in presence of cone. H₂SO₄.
© ethene reacts with water in presence of sulphuric acid.
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9. What is bauxite? What are the main impurities that are found in this ore? Briefly describe how the ore is purified.
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10. (a) Describe briefly the action of heat on sulphur. (6) Write a reaction to show
(i) the reducing action of hydrogen,
(ii) the dehydrating action of cone. H₂ SO₄ on sugar.
(iii) the catalytic oxidation of ammonia to nitric oxide.

Or

(a) Describe an activity to show that hydrogen is lighter than air.
(b) Choose from the following gases to answer the questions below: ammonia, carbon dioxide, hydrogen, nitrogen, oxygen, sulphur dioxide. Each gas can be used once, more than once or not at all. Name a gas which (i) is used to bleach wood pulp.
(ii) is used in the manufacture of fertilizers.
(iii) could be developed as an alternative fuel for the future.
(iv) changes acidified potassium dichromate from orange to green.
(v) is evolved at the anode during the electrolysis of alumina dissolved in
cryolite.
(vi) is evolved when ammonia is passed over heated copper(II) oxide.
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1. What are endothermic reactions? Give one example of an endothermic reaction.
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2. Write the equation for the reaction which takes place when sodium oxide reacts with water.
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3. What is Plaster of Paris? How is it obtained?
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4. (a) Define pH of a solution.
(b) Determine the pH of 0.005 M sulphuric acid.
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5. Explain the following terms: (a) Mortar
(b) Concrete.
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6. (a) How is propanone prepared commercially? Give the reactions involved in it. (b) What is the advantage of using vulcanised rubber over natural rubber?
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7. A non-metal belonging to group 16 of the periodic table is mined by a special technique based on its low melting point. Identify the non-metal and name the process by which it is extracted. With the help of a labelled diagram, explain the method of its extraction.
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8. What would you observe when sulphur dioxide is passed through (a) lime water,
(b) acidified potassium dichromate solution?
Write the chemical reactions that take place.
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9. Write a reaction to show the
(a) addition of HCN to methanal.
(b) oxidation of methanal by Fehling’s reagent.
© oxidation of ethanol by CrO₃ in CH₃COOH.
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10. (a) Draw a flow chart for the manufacture of ammonia by Haber process.
(b) (i) How will you separate hydrogen from a mixture of carbon dioxide and hydrogen?
{ii) How is granulated zinc prepared? Why is it preferred over metallic zinc for the preparation of hydrogen gas in the laboratory.

Or

(a) Draw a labelled diagram of the apparatus which could be used to purify a block of impure copper.
(b) Aluminium oxide is an amphoteric oxide. Explain what is meant by amphoteric.
© (i) Write a chemical equation for the reaction between methane and steam.
(ii) Vegetable ghee is manufactured by the reaction between hydrogen and vegetable oils in the presence of a catalyst. What types of bonds must be present in the vegetable oil for this reaction to take place?
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1. What is efflorescence? Name one compound which shows efflorescence.
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2. Which process is used for the enrichment of
(a) sulphide ores, (b) oxide ores?
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3. Name two metals which are purified by liquation.
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4. A white coloured compound reacts vigorously with water. The solution formed turns red litmus blue. It is used in the blast furnace to remove the sand from the ore. Write the commercial name of the compound and its chemical formula. Write two other uses of this compound.
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5. Write two points of differences between roasting and calcination.
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6. (a) At 298 K, the equilibrium concentrations of the reactants and products for
the reaction, N₂ (g) + 3H₂ (g) = 2NH₃(g) are as follows:

[N₂] = 0.001 M; [H₂] = 0.02 M and [NH₃] = 0.5 M. Calculate the equilibrium constant at this temperature.

(b) If temperature is increased, what effect it will have on the value of the equilibrium constant of the above reaction? The formation of NH₃ is an exothermic reaction.
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7. Explain the following terms:
(a) Esterification
(b) Saponification
© Decarboxylation.
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8. (a) What is Tollen’s reagent?
(b) Which class of compounds give Tollen’s test?
© Write the reactions involved in the Tollen’s test.
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9. (a) What are alloys? Why are alloys made?
(b) Name an alloy of
(i) aluminium used in the construction of aircrafts.
(ii) iron used for making surgical instruments.
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10. (a) Write one reaction in each case to illustrate the following: (i) reducing action of ammonia (ii) oxidising action of sulphur dioxide.
(b) In the Contact process for the manufacture of sulphuric acid (i) name the catalyst.
(ii) name the substance in which sulphur trioxide is dissolved. (iii) name the substance which is diluted with water.
© The crystal of the substance ‘X’ is blue in colour. When it is placed in conc.H₂SO₄, it becomes white. Identify ‘X’ and explain the observation.

Or

(a) Liquid hydrogen is used as a rocket fuel. It is used in space shuttles.
(i) Another gas must be carried by a space shuttle in order to burn the hydrogen. What is the name of this gas? (ii) Suggest a reason why the space shuttle carries liquid hydrogen rather than hydrogen gas.
(b) (i) It has been suggested that hydrogen could be developed as an alternative fuel for the future.
Suggest one reason hydrogen has over fossil fuels.
(ii) Give one other industrial use of hydrogen.
© Write a chemical equation for the laboratory preparation of hydrogen gas.
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1. A substance ‘X’ on exposure to air smells of chlorine. What is the general name of ‘X’? Write its chemical formula.
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2. Aluminium was first extracted from aluminium chloride by using sodium according to the following equation.
AlCl₃+ 3Na = Al + 3NaCl

What is the role of sodium in the above process?
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3. What is an amalgam?
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4. (a) Write the names of raw materials that are required for the manufacture of ortland cement. (b) Why is gypsum added to cement?
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5. What happens when sulphur reacts with
(a) concentrated sulphuric acid, and (b) concentrated nitric acid?
Write the chemical equations of the reactions.
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6. (a) What does dynamic equilibrium mean?
(b) Write an expression for the equilibrium constant for the following reactions:
(i) 2NO(g) + O₂(g) = 2NO₂(g)
(ii) N₂ (g) + 3H₂ (g) = 2NH₃ (g)

© State the particles present in an aqueous solution of acetic acid (ethanoic acid).

7. What is fermentation? How is ethanol obtained by fermentation of sugars?
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8. (a) (i) What is meant by functional group in an organic compound?
(ii) Write the names of two compounds which contain a carbonyl group.
(b) What is a monomer? Write the name of the monomer of teflon.
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9. Differentiate between metals and non-metals on the basis of following characteristics:
(a) Nature of oxides
(b) Electrical conductivity
© Oxidising or reducing action.
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10. (a) Name the chief ore of iron.
(6) Write the name of the raw materials that are used in the production of iron in the blast furnace. © Write the reactions that take place in the blast furnace during the extraction of iron.

Or

(a) (i) What is a promoter? Name the substances that are used as promoters in the manufacture of ammonia by Haber process.
(ii) How is ammonia separated from a mixture of ammonia, nitrogen and hydrogen?
(b) It is said that while preparing dil. H₂SO₄, water should never be added to cone. H₂SO₄ but conc. H₂SO₄ should be added to water slowly. Why?
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1. Mention the different types of sacred monuments that we have inherited from the past. What does the large variety of sacred monuments reflect?
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2. Give a brief account of Buddhist and Jain literary works.
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3. Mention in brief the measures you can suggest to conserve and protect the forests.
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4. Compare and contrast the climatic requirements and soil requirements of wheat and rice.
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5. What are soils? How are they formed?
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6. Distinguish between metallic and non-metallic minerals.
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7. (a) What is an economy?
(b) What do you mean by economic development?
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8. What do you mean by privatisation?
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9. Give a brief account of the international consumer movement.
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10. Mention constitutional provisions to protect the rights of children.
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11. Describe the mechanism of caste system as practised in the past.
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12. What is NAM? Has NAM lost its relevance with the end of the cold war?
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13. Distinguish between revolutionaries and terrorists.
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14. Discuss the threats to our heritage.
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15. Mention some important elements of our literary heritage.
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16. Why is cotton textile industry located in Maharashtra and Gujarat?

Or

Describe the importance of unsurfaced roads in the Indian economy.
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17. What measures will you suggest to face the challenge of globalisation in the area of agriculture?

Or

Why do you think that nuclear energy is bound to play an increasingly important role in India?
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18. What do you mean by sex ratio? Account for the declining sex ratio in India.
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19. What are the dimensions of gender inequity in India? What do you mean by gender-empowerment?
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20. Give a brief description of important temples in east and south India.
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21. What role does power play in industrialisation of our country? What steps would you suggest to conserve energy?
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22. Outline the steps that have been taken for improvement and modernisation of Indian railways after independence.
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23. Give a brief review of important fruits in India.

Or

Describe, in brief, the cycle of agricultural seasons in India.
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24. What is the magnitude of poverty in India? Has the number of persons living below the line of poverty declined during the last three decades?
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25. How has globalisation affected the international migration of labour? What has been the response of the developed countries and the developing countries to these trends?
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26. What are Human Rights? What is the Universal Declaration of Human Rights?

Or

Name some important insurgent groups in North-East.
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27. (a) On an outline map of India, show the following:
(i) Garo-Khasi Jaintia Hills;
(ii) River Kosi;
(iii) River Tungabhadra.
(b) On an outline map of India, show the important sugar-grow ing areas in India.
© On an outline map of India, locate and label the following:
(i) Mangalore Port;
(ii) Guwahati Software Technology Park;
(iii) Ahmedabad—Vadodara Industrial region.
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