Corundum is
AI2(SO4)3
AI2O3.H2O
AI2O3.2H2O
AI2O3
The thermite process involves the use of
AI2O3 and Fe
AI2O3 and Fe2O3
AI and FeQ
AI and Fe2O3
Inorganic graphite is
B2O3
BN
B4C
B3N3H6
Which of the following sublimes on heating?
AIF3
AICI3
AIBr3
AII3
Rubles and sapphire are chemically
AI2O3 + Ag2O3
Ag2O + Au2O3
AI2O3 + C
The type of hybridization of boron in diborane is
sp
sp2
sp3
sp3d2
Alumnium becomes passive in
Conc: HNO3
H2CrO4
HCIO4
All
Borax is not used
As a styptic to stop bleeding
In making enamel and pottery glazes
As a flux in soldering
In making optical glass
The blue colored mineral ‘Lapis Lazuli’ which is used as a semiprecious stone is a mineral of the following class
Sodium aluminosilicate
Zinc cobaltate
Basic copper carbonate
All the above
Which of the following is not correct in case of boron nitride, BN?
It is a good insulator
It is hard because in one of the modifications it has diamond (zinc blende) like structure
It shows magnetc properties
It is chemically unreactive