CBSE
Important ore of zinc is :
calamine
cryolite
zinc blende
malachite
Maximum number of molecules of CH3I that can react with a molecule of CH3NH2 are :
3
4
2
1
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
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
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
Which of the following is not the correct match?
Leaching : Ag
Zone refining : Sn
Liquation : Pb
van Arkel : Zr