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Name the gas evolved when concentrated HCI is added to powdered potassium dichromate. On passing the evolved gas through acidified KBr solution, the solution turns brown. Write the balanced equations for the reactions involved. |
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Answer» Solution :`Cl_(2)` gas is evolved when conc. HCL reacts with powdered `K_(2)Cr_(2) O_(7)`. `{:(K_(2)Cr_(2)O_(7)+8 HCI rarr 2 KCI + 2 CrCl_(3) + 4 H_(2)O + 3 [O]),(""2 HCl + [O] rarr [H_(2)O + Cl_(2)] xx 3),(bar(K_(2)Cr_(2)O_(7)+14HCl rarr 2 KCL + 2 CrCl_(3) + 3 Cl_(2) + 7 H_(2)O)):}` SINCE `Cl_(2)` is a stronger oxidising agent than `Br_(2)`, therefore, when `Cl_(2)` is passed through acidified KBr solution. `Br_(2)` is liberated which turns solution brown. `Cl_(2) + 2 KBr rarr 2 KCl + Br_(2)` (turns solution brown) |
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