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Dear students, this is a question from salt analysis.
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Silver, lead and mercuracine, these are group 1 radicals.
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These are group 1 cations.
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And this is a test for question on the test for group 1 cations.
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The first question is a white basalt formed when concentrated h .l is added to the solution.
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This is due to the formation of the chlorides.
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Ag plus reacts with hcl to form agcl.
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So let us write here, cl minus.
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So it forms a gcl which is white.
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Similarly, pb2 plus reacts with chloride ions from hcl to form pbcl to similarly mercury iron reacts with chloride ions to form mercurice chloride.
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All these are white.
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Now, the second step is water is added to the white precipitate and the mixture is heated.
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Sodium dichromate is added to the supernatal liquid, but no yellow precipitate is formed.
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We know lead chloride is more soluble in hot water compared to agcl and mercurose chloride.
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Therefore when we are heating by addition of water, then what happens? laid chloride goes into solution forming lead ions.
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Lead chloride goes into solution forming lead ions, then when we are adding sodium dichromate to this hot solution, then lead chromate is getting formed.
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Pb cero4...