CBSE
Which of the following is philosopher's wool ?
ZnO
HgO
Ag2O
CuO
When H2S gas is passed in a metal sulphate solution in presence of NH4OH, a white precipitate is produced. The metal is identified as:
Zn
Fe
Pb
Hg
Anhydrous ferric chloride is prepared by:
dissoving Fe(OH)3 in concentrated HCl
dissolving Fe(OH)3 in dilute HCl
passing dry HCl overheated iron scrap
passing dry Cl2 gas overheated iron scrap
For which element the inertness of the electron pair will not be observed?
Sn
Fe
Pb
In
84Rn219 is a member of actinium series. The other member of this series is-
89Ac225
90Th232
15P35
92U235
Which one is malachite from the following?
Cu(OH)2
Fe3O4
CuCO3.Cu(OH)2
CuFeS2
Composition of azurite mineral is
CuCO3.CuO
Cu(HCO3)2.Cu(OH)2
2CuCO3.Cu(OH)2
CuCO3.2Cu(OH)2