| 1. | A student added dilute HCl to a test tube containing zinc granules and made following observations ? | |
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a gas evolved which burnt with a pop sound
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the solution becomes green in colour
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the zinc surface became dull and black
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the solution remained colourless
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Report Question| 2. | A compound used for whitewashing is ? | |
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Limestone
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Blue vitriol
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Slaked Lime
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Quick lime
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| 3. | Lead nitrate Pb(NO3)2 on heating forms Lead oxide (PbO) solid and Nitrogen dioxide gas. What are the color of lead oxide and nitrogen dioxide ? | |
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Yellow, Brown
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Yellow, Colourless
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White, Brown
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White, Colourless
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| 4. | What is observed when a solution of potassium iodide is added to silver nitrate solution ? | |
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Agl is soluble in water
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yellow precipitate of Agl is formed
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White precipitate of silver iodide is formed
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No reaction takes place
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| 5. | To facilitate the electrolysis of water we add a few drops of acids like sulfuric acid or salts like NaCl because ? | |
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It prevents the decomposition of electrodes used
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None
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It acts as a catalyst
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It increases the electrical conductivity of water
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| 6. | Which of the following gases can be used for storage ? | |
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Carbon dioxide or Helium
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Helium or Nitrogen
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Nitrogen or Oxygen
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Carbon dioxide or Oxygen
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| 7. | Zinc reacts with silver nitrate to form which compounds ? | |
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Ag + Zn(NO3)3
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AgNO3 + Zn(NO3)2
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Zn(NO3)2 + Ag
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ZnNO3 + Ag
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| 8. | Which of the following are exothermic processes? (i) Reaction of water with quick lime (ii) Dilution of an acid (iii) Evaporation of water (iv) Sublimation of camphor (crystals) ? | |
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(iii) and (iv)
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(i) and (iv)
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(i) and (ii)
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(ii) and (iii)
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| 9. | Silver article turns black when kept in the open for a few days due to formation of ? | |
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Ag2S
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AgS
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AgSO4
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H2S
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| 10. | Consider the given statements and choose the incorrect one ? | |
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The bubbles of hydrogen gas are produced, when zinc granules reacts with dilute sulphuric acid
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None of the above
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Hydrogen gas is evolved when dilute hydrochloric acid is poured over sodium carbonate
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Hydrogen gas is evolved when magnesium reacts with a dilute acid
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