InterviewSolution
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An aqueous solution of a mixture of two inorganic salt , when reated with diute HCI ,Gave a precipitate (P) and a filrate (Q) .The precipitate P was found to dissolve in hot water .The filrate (Q) remained unchanged , white tracated with `H_(2)S` in a difute mineral acid medium .However it gave a precipitate (R ) with `H_(2)S` in an ammoniacal medium .THe precipitate R give a coloured solution (S ) when treated with `H_(2)O_(2)` to an aq2ueous `NaOH` medium The coloured solution S containA. `Fe_(2)(SO_(4))_(3)`B. `CuSO_(4)`C. `ZnSO_(4)`D. `Na_(2)CrO_(4)` |
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Answer» Correct Answer - d The precipitate `(P)` contains `Pb^(2+)` `Pb^(2+) + 2HCI rarr PbCI^(2+) overset(Hot) underset(water)(to) Solution` The filtrate `(Q)` contains `Cr^(+3)`, since it does give any precipitate with `H_(2)S` in acide medium .But gives precipitate`(R )` with `H_(2)S` in alkline medium So, `R` is `Cr(OH)_(3)` and S is `Na_(2)CrO` `Cr^(+3) overset(Ammonical) underset(H_(2)S)to Cr(OH)_(3) overset(H_(2)O_(3))underset(NaOH)to underset(yellow soln)(Na_(2)CrO_(4))` |
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