A yellow turbidity, sometimes appears on passing H_(2)S gas ever in the absence of the second group radicals. This happens because

A yellow turbidity, sometimes appears on passing H_(2)S gas ever in th

1.	A yellow turbidity, sometimes appears on passing H_(2)S gas ever in the absence of the second group radicals. This happens because
Answer» SULPHUR is present in the mixture as an impurity the fourth group radicals are precipitated as sulphides `H_(2)S` is oxidised by some ACIDIC radical present in solution the third group radicals are precipitated Aqueous sodium hydroxide reacts with a METAL ion Solution :`H_(2)S` oxidised by some acid radical (e.g. `NO_(3)^(-)` salt) present in the mixture is to sulphur which APPEARS as yellow turbidity