Class 11th
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New answer posted
8 months agoContributor-Level 10
It necessary to use acetic acid and not sulphuric acid for acidification of sodium extract for testing sulphur by lead acetate test because sulphuric acid will react with lead acetate to form a white precipitate of lead sulphate which will interfere in the test of sulphur.
Pb (OCOCH3)2 + H2SO4 →PbSO4 + 2CH3COOH
New answer posted
8 months agoContributor-Level 10
CO2 is acidic in nature and therefore, it reacts with the strong base KOH to form K2CO3.
2KOH + CO2 ? K2CO3+ H2O.
New answer posted
8 months agoContributor-Level 10
No. CCl4 is a completely non-polar covalent compound whereas AgNO3 is ionic in nature. Therefore, they are not expected to react and thus a white precipitate of silver chloride will not be formed.
New answer posted
8 months agoContributor-Level 10
It is because in steam distillation the sum of vapour pressure of organic compound and steam should be equal to atmospheric pressure.
New answer posted
8 months agoContributor-Level 10
Sublimation can be used for the separation of the two compounds because camphor can sublime whereas CaSO4 does not.
New answer posted
8 months agoContributor-Level 10
Organic compound is fused with sodium metal so as to convert organic compounds into NaCN, Na2S, NaX and Na3PO4. Since these are ionic compounds and become more reactive and thus can be easily tested by suitable reagents.
New answer posted
8 months ago12.25. Why is nitric acid added to sodium extract before adding silver nitrate for testing halogens?
Contributor-Level 10
Nitric acid is added to sodium extract so as to decompose NaCN to HCN and Na2S to H2S and to expel these gases.
NaCN + HNO3 ——-> NaNO3 + HCN
Na2S + 2HNO3 ——> 2NaNO3 + H2S
New answer posted
8 months agoContributor-Level 10
This is the simplest form of chromatography. Here a strip of paper acts as an adsorbent. It is based on the principle which is partly adsorption. The paper is made of cellulose fibres with molecules of water adsorbed on them. This acts as stationary phase. The mobile phase is the mixture of the components to be identified prepared in a suitable solvent.
New answer posted
8 months agoContributor-Level 10
Estimation of halogens: It involves oxidising the organic substance with fuming nitric acid in the presence of silver nitrate. The halogen of the substance is thus converted to silver halide which is separated and weighed:
Weight of organic compound = W gm
weight of silver halide = x g.
% of halogen =
Estimation of sulphur: The organic substance is heated with fuming nitric acid but no silver nitrate is added. The sulphur of the substance is oxidised to sulphuric acid which is then precipitated as barium sulphate by adding excess of barium chloride solution. From the weight of BaSO4 so obtained the percentage of sulphur can
New answer posted
8 months agoContributor-Level 10
(i) Dumas method: The nitrogen containing organic compound, when heated with copper oxide in an atmosphere of carbon dioxide, yields free nitrogen in addition to carbon dioxide and water
(ii)Kjeldahl's method: A known mass of the organic compound is heated strongly with conc. H2SO4, a little potassium sulphate and a little mercury (a catalyst). As a result, the nitrogen present in the organic compound is converted to ammonium sulphate.
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