» CBSE Science Sample Question Paper : Set I : CBSE Sample Question Papers

Section - A

1. What is the effect of an increase in temperature on the rate of a chemical reaction ?
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2. Name any two isotopes which readily undergo nuclear fission.
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3. Name the functional groups present in :
(a) CH,COOH
(b) CH,COCH,
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4. Why does it take longer to burn wet wood ?
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5. Why are Zirconium, Titanium and Chromium classified as strategic metals ?
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6. Define the terms:
(a) Astronomical Unit
(b) Light year
Give approximate value of each in SI units.
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7. Explain giving reasons :
(i) Tartaric acid is a component of baking powder used in making cakes.
(it) Gypsum, CaSO₄. 2H₂O is used in the manufacture of cement,
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8. Calculate the energy released ( in MeV) when 1 kg mass is completely converted into energy. (Take 1 MeV- 1.6 x l0^-13 J, C = 3,0 x 10⁸ ms^-1 )

OR
When Uranium undergoes fission, 0.1 % of the total mass is converted into energy. Calculate the total amount of energy released in Joules during an explosion of in atom bomb which contains 5 kg of Uranium.
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9. When a copper wire is left in silver nitrate solution, it is observed that the solution turns bluish green, (i) Explain this observation. (ii) Write the balanced chemical equation 10 represent the change taking place.
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10. State Right Hand Thumb rule to find the direction of the magnetic field around a current carrying straight conductor. How will this magnetic field be affected on ?
(a) increasing the current through the conductor ?
(b) changing the direction of flow of current in the conductor ?
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11. (a) Name the product formed when melhanol undergoes controlled oxidation.
(b) Describe with necessary chemical equations the lest you would perform to identify the above product.
© Name the compound formed when ethanoic acid reacts with ethanol in the presence of concentrated sulphuric acid.

OR
(a) Propanone can be manufactured from Cumene. Write the corresponding chemical equation.
(b) Name the compound formed when propanone is reduced. Which reducing agent is generally used in this process ?
© How is propanone converted to ethanoic acid ?
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12. Two identical resistors, each of resistance 10 ohms, are connected (/) in series (it) in parallel, in turn. to a battery of 6 volts. Calculate the ratio of power consumed in the combination of resistors in two cases.
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13. An aqueous solution has hydrogen ion concentration, [H + ] - 1.0 x 10^-10 mol L^-1
(a) Determine the pH of this solution.
(b) Is the solution acidic, basic or neutral?
© Will the pH of the above solution increase or decrease on adding a drop of 1M HCL to it ? Justify your answer.
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14. Draw a labelled diagram of a dry cell. Write the chemical equations involved
(i) at the anode
(it) at the cathode while the cell is working. 3
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15. Distinguish between polar and equatorial orbits of artificial satellites, Which of the above two orbits
is suitable for a (i) geostationary satellite (ii) satellite used for weather forecasting ?

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How do we locate the position of the pole star in the sky? Why is the pole star so special ? 3
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