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Why a salt containing lead turns black i...

Why a salt containing lead turns black in colour, when placed for a long time in laboratory?

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`Pb^(2+)+H_(2)S ("atmospheric")toPbS darr("black")+2H^(+)`.
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RESONANCE ENGLISH-QUALITATIVE ANALYSIS PART 1-EXERCISE 1 PART 2 QUALITATIVE ANALYSIS
  1. When calomel reacts with ammonia solution, a black precipitate is fome...

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  2. What products are formed when precipitate formed by the reaction of Hg...

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  3. Why a salt containing lead turns black in colour, when placed for a lo...

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  4. Name one chloride which is soluble in hot water as well as in excess o...

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  5. Does mercuric sulphide dissolve in sodium sulphide solution (of 2M)?

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  6. What happens when white precipitate of Bi(OH)(3) is boiled ?

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  7. Why Na(2)S cannot be used in place of H(2)S (in presence of HCl) as a ...

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  8. Is their any reaction other then cyanide reaction which can be used fo...

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  9. Which basic radical is tested with the help of alkaline sodium stannit...

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  10. What happens when ammonium sulphide solution reacts with a solution co...

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  11. Can Cr(III) salt be oxidised to Cr(VI) salt by potassium (or ammonium)...

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  12. Do Fe(III) salts and Fe(II) salts both give red colouration with dimet...

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  13. Which colour precipitate is fomed by Fe(II) salt with potassium ferroc...

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  14. Which basic radical(s) decolourize acidic KMnO(4) ?

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  15. Partial precipitation of Mn^(2+) as Mn(OH)(2) occurs with ammonia solu...

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  16. What happens when Mn(II) ions free from chloride ions react with acidi...

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  17. Why Zn(II) salt is not precipitated as Zn(OH)(2) by ammonia solution i...

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  18. What will happen if the precipitation of V^(th) group cation by ammoni...

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  19. What happens when ammonium sulphate solution is added to a solution c...

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  20. Which colour precipitate is obtained when a solution of Ca^(2+) ions r...

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