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Take little water in a test tube add two drops of phenolphthalein in it Same quantity of Kerosene is added to the mixture and a small piece of sodium is dipped in it.1. What kind of colour formed in the test tube? Why?2. Which gas is bubbled on the surface of sodium metal?3. Write balanced equation of the reaction between sodium and water.4. What products occurs when Iron reacts with water vapour?5. Lustre of magnesium disappeared fast when it placed in open space why?6. Verdigris formed on copper utensils disappeared after some days why?7. Lustre of aluminium utensils disappear after some days. Why?8. Write down the equation for the reaction between CuSO4 and iron nail? What type of reaction is this? |
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Answer» 1. Water become pink in colour. Because when phenolphthalein is added to water it becomes alkaline. 2. Hydrogen 3. 2Na(s) + 2H2O(l) → 2NaOH(aq) + H2(g). Fe3O4 (Iron Oxide) and Hydrogen gas. 4. When Magnesium is kept in open space it reacts with atmosphere air and a light coat of magnesium oxide is formed. This is the reason for Magnesium to lose its lustre. 5. The copper in copper utensils react with atmospheric air and forms copper oxide. Due to this verdigris are formed on Copper utensils. 6. Aluminium reacts with atmospheric air and Aluminium oxide is formed. This process takes place slowly. Hence Aluminium utensils loose their lustre. CuSO4 + Fe → FeSO4 + Cu. Redox reaction. |
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