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InterviewSolution
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When conc. `H_(2)SO_(4)` was added to an unknown salt present in a test which was heated, a brown gas (A) was evolved. The gas intenstified when copper turning were also added into the test tube. On cooling, the gas (A) changed into a colourless liquid (B). (a) Identify the gases A and B (b) Write equations for the reactions involved. |
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Answer» The available data suggests that the salt is some nitrate of a metal and the chemical reactions involved are listed : `MNO_(3)+H_(2)O("conc.") overset("Heat")to MHSO_(4)+HNO_(3)` `4HNO_(3)overset("Heat")to underset((A))underset("Brown gas") (4NO_(2)+2H_(2)O+O_(2))` Upon adding some copper turning, more fumes of gas (A) were evolved and therefore, the brown colour was intestified. `Cu+4HNO_(3) overset("Heat")to Cu(NO_(3))_(2)+2H_(2)O+2NO_(2)` `underset((B))underset("Brown gas")(2NO_(2))underset("Heat")overset("Cool")harr underset((B))underset("Colourless liquid")(N_(2)O_(4))` |
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