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K2Cr2O7  when reacts with cold conc. H2SO4 gives red crystal of

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Important Questions on The d- and f-Block Elements

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The number of water molecules not coordinated to copper ion directly in CuSO4·5H2O, is
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In alkaline medium, the reaction of hydrogen peroxide with potassium permanganate produces a compound in which the oxidation state of Mn is
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The sum of the total number of bonds between chromium and oxygen atoms in chromate and dichromate ions is ______________.
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The ionic charges of manganate and permanganate ion are respectively
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When XO2 is fused with an alkali metal hydroxide in presence of an oxidizing agent such as KNO3; a dark green product is formed which disproportionate in acidic solution to afford a dark purple solution. X is:
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Thermal decomposition of a Mn compound X at 513 K results in compound Y, MnO2 and a gaseous product. MnO2 reacts with NaCl and concentrated H2SO4 to give a pungent gasZ . X, Y and Z, respectively, are:
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Which of the following is not formed when H2S reacts with acidic K2Cr2O7 solution ?
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Name the gas that can readily decolourise acidified KMnO4 solution.
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When a mixture of manganese dioxide, potassium hydroxide and potassium chlorate is fused, the product obtained is
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Which one of the following statements is correct when SO2 is passed through acidified K2Cr2O7 solution?
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A metal A on heating in nitrogen gas gives compound B. B on treatment with H2O gives a colourless gas which when passed through CuSO4 solution gives a dark blue-violet coloured solution. A and B respectively, are:
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The manganate and permanganate ions are tetrahedral, due to:
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A mixture of NaCl and K2Cr2O7 is heated with conc. H2SO4, deep red vapours and formed. Which of the following statement is false ?
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When dil. sulphuric acid reacts with aqueous solution of potassium chromate, the colour changes from yellow to orange. This shows that
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Acidified potassium dichromate is treated with hydrogen sulphide. In the reaction, the oxidation number of chromium
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MnO2 when fused with KOH and oxidized in air gives a dark green compound X. In acidic solution, X undergoes disproportionation to give an intense purple compound Y and MnO2. The compounds X and Y, respectively, are
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The colour of KMnO4 is due to: [where M metal, L ligand]