InterviewSolution
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InterviewSolution
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EXERCISES 9. What happens when(a) Dilute sulphuric acid is poured on a copper plate?(b) Iron nails are placed in copper sulphate solution?Write word equations of the reactions involved.10. Saloni took a piece of burning charcoal and collected the gas evolved in atest tube.(a)(b)How will she find the nature of the gas ?Write down word equations of all the reactions taking place in thisprocess.11. One day Reeta went to a jeweller's shop with her mother. Her mother gavean old gold jewellery to the goldsmith to polish. Next day when they broughtthe jewellery back, they found that there was a slight loss in its weight.Can you suggest a reason for the loss in weight? |
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Answer» 9. (a) when dilute Sulfuric acid poured on Copper plate then Copper sulphate is formed as a precipitate and Hydrogen gas will be liberated . (b)When iron nail is placed in the solution of Cupper sulphate solution , as Iron is more reactive in comparison to Copper , It will displace Copper from it's solution and Iron sulphate will be formed along with this Cupper will formed.10 . here the liberated gas is CO2We can know it's presence by passing it through Ca(OH)2.If it forms whit precipitate then the evolved is certainly Carbon dioxide .It's EQUATION will be Ca(OH)2+CO2--------->CaCO3+H2Ohere CaCO3 is the white precipitate formed in the reaction.11. To POLISH a gold ORNAMENT, it is dipped in a liquid CALLED aqua regia (a mixture of hydrochloric acid and nitric acid). On getting the environment of aqua regia, the outer LAYER of gold dissolves and the inner shiny layer appears. The dissolving of the layer causes a reduction in the weight of the jewellery. |
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