Which of the following compounds gives a yellow residue when heated and also reacts with aqueous sodium hydroxide to give a white gelatinous precipitate soluble in excess sodium hydroxide solution?

Efranklyn

5 years ago

Lead, Zinc and Aluminium gives similar test with NaOH all are also soluble in excess NaOH
But for the fact that white gelatinous is used instead of white ppt and also a yellow deposits with indicate the presence of Sulphur then
C is correct not B myschool check well please

talk2kb

2 years ago

Options B is very correct
by Elimination Method option A&D are out
both ZnCO3 & Al2(SO4)3 and also Magnesium will give the white precipitate with Sodium hydroxide but the Question says in EXCESS SODIUM HYDROXIDE definitely in excess sodium hydroxide Aluminium will re-dissolve its white precipitate only Zinc and Magnesium will not
options B is very correct

Toppr

11 months ago

The answer is not correct,it is meant to be PbCO3,since they question said it gave a yellow residue and only pb can give a yellow residue,zn will give a white residue