A white powder (A) on heating gave a non-combustible gas and a residue (B). The white compound A on reaction with `H_(2)S` in alkaline medium forms a precipitate (C ) which dissolves in dil. `CH_(3)COOH`. (B) can be disssolved in dil HCl to prepare a solution which gives a white precipitate with `K_(4)[Fe(CN)_(6)]`. Compuound B isA. `CaO`B. `CuO`C. `CoO`D. `ZnO`

A white powder (A) on heating gave a non-combustible gas and a residue

1.	A white powder (A) on heating gave a non-combustible gas and a residue (B). The white compound A on reaction with `H_(2)S` in alkaline medium forms a precipitate (C ) which dissolves in dil. `CH_(3)COOH`. (B) can be disssolved in dil HCl to prepare a solution which gives a white precipitate with `K_(4)[Fe(CN)_(6)]`. Compuound B isA. `CaO`B. `CuO`C. `CoO`D. `ZnO`
Answer» Correct Answer - D `ZnCO_(3)overset(Delta)(rarr)underset((B))(ZnO)+CO_(2)` yellow when hot but white when cold

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When a metal rod M is dipped into an aqueous colourless concentrated solution of compound N, the solution turns light blue. Addition of aqueous `NaCl` to the blue solution gives a white precipitate O. Addition of aqueous `NH_(3)` dissolves O and gives an intense blue solution. The final solution containsA. `[Pb(NH_(3))_(4)]^(2+)` and `[CoCl_(4)]^(2-)`B. `[Al(NH_(3))_(4)]^(3+)]` and `[Cu(NH_(3))_(4)]^(2+)`C. `[Ag(NH_(3))_(2)]^(+)` and `[Cu(NH_(3))_(4)]^(2+)`D. `[Ag(NH_(3))_(2)]^(+)` and `[Ni(NH_(3))_(6)]^(2+)`
`(NH_(4))_(2)Cr_(2)O_(7)` on heating gives a gas which is also given byA. Heating `NH_(4)NO_(2)`B. Heating `NH_(4)NO_(3)`C. `Mg_(3)N_(2)+H_(2)O`D. `Na(comp.)+H_(2)O`
A sodium salt on treatment with `MgCl_(2)` gives white precipitate only on heating. The anion of sodium salt isA. `HCO_(3)^(-)`B. `CO_(3)^(2-)`C. `NO_(3)^(-)`D. `SO_(4)^(2-)`
To a metal nitrate, when KI solution is added, a black precipitate is produced at first , on additing excess of KI, orange solution is produced. Identify the meatl ionA. `Hg^(2+)`B. `Bi^(3+)`C. `Cu^(2+)`D. `Pb^(2+)`
A metal nitrate reacts with `KI` to give a black precipitate which on addition of excess of `KI` convert into orange colour solution. The cation of metal nitrate isA. `Hg^(2+)`B. `Bi^(3+)`C. `Sn^(2+)`D. `Pb^(2+)`
A metal nitrate reacts with `KI` to give a black precipitate which on addition of excess of `Kl` is converted into orange colour solution.The cation of the metal nitrate is :A. `Hg^(2+)`B. `Bi^(3+)`C. `Pb^(2+)`D. `Cu^(+)`
Assertion : Change in colour of the acidic solution of breath is used as a test for drunken driver. Reason : Change in colour is due to complexation of alcohol with potassium dichromate.
`S_(1) :` Silver iodide is fairly soluble in hypo solution. `S_(2) :` Heavy metal chloride like `AgCl,HgCl_(2)` etc. also respond to Chromyl chloride test. `S_(3) :` Bromine reacts with `KI` liberating violet vapours of iodine. `S_(4) :` Diphenylamine reagent test is also given by nitrites chlorates, bromates, iodates, etc. in addition to `NO_(3)^(-)`A. `T T T F`B. `T F T T`C. `T T F F `D. `F F T T `
Statement I Sulphate is extimated as `BaSO_(4)`, not as `MgSO_(4)`. Statement II Ionic radius of `Mg^(2+)` is smaller than that of `Ba^(2+)`.
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