For testing halogens in an organic compound with AgNO3 solution, sodium extract (Lassaigne’s test) is acidified with dilute HNO3. What will happen if a student acidifies the extract with dilute H2 SO4 in place of dilute HNO3?


For testing halogens in an organic compound with AgNO3 solution, sodium extract (Lassaigne’s test) is acidified with dilute HNO3becauseif the compound contains either nitrogen or sulphur or both along with halides, they also react with silvernitrate to form precipitates, so to decompose sodium sulphide and sodium cyanine if present so that they will not precipitate masking the precipitates of silver halides nitric acid is added. If dilute H2 SO4is added then sodium sulphide and sodium cyanine are not decomposed thereby we will not get the correct result if halides are also present.


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