CBSE
Slag formed in blast furnace, removes the impurity of
SiO2
CaO
CO2
FeO
The purpose of smelting an ore is to :
oxidise it
reduce it
obtain an alloy
separate volatile impurities
Aluminium becomes passive on treatment with :
dil. HNO3
conc. HNO3
dil. H2SO4
none of these
Important ore of zinc is :
calamine
cryolite
zinc blende
malachite
When CO2 is passed through solution of sodium aluminate, precipitate of which compound is formed?
Al(OH)3
Al2O3
Na2CO3
No ppt
Oils can be converted into fats by :
hydrogenolysis
hydrogenation
decarboxylation
hydration
Which method is not used for the extraction of Al ?
Van - Arkel
Serpeck
Baeyer
Hall - Heroult
Which of the following is not the correct match?
Leaching : Ag
Zone refining : Sn
Liquation : Pb
van Arkel : Zr
What is the role of aniline or cresol when added in a froth floatation process?
Stabilizer
Depressant
Wetting agent
All of these
Maximum number of molecules of CH3I that can react with a molecule of CH3NH2 are :
3
4
2
1