When CO2 is passed through solution of sodium aluminate, precipitate of which compound is formed?
Al(OH)3
Al2O3
Na2CO3
No ppt
Which of the following is not the correct match?
Leaching : Ag
Zone refining : Sn
Liquation : Pb
van Arkel : Zr
The purpose of smelting an ore is to :
oxidise it
reduce it
obtain an alloy
separate volatile impurities
What is the role of aniline or cresol when added in a froth floatation process?
Stabilizer
Depressant
Wetting agent
All of these
Aluminium becomes passive on treatment with :
dil. HNO3
conc. HNO3
dil. H2SO4
none of these
B.
conc. HNO3
Aluminium becomes passive on treatment with conc. HN03 , due to the formation of aluminium oxide on its surface which prevents it from further action .
Carbon and CO gas are used to reduce which of the following pairs of metal oxides for extraction of metals?
FeO, SnO
SnO, ZnO
BaO, Na2O2
FeO, ZnO