The mixture of conc.HCl and HNO3 made 3:1 ratio contains
ClO2
NOCl
NCl3
N2O4
Which is not a mineral of aluminium?
Anhydrite
Bauxite
Corundum
Diaspore
Which of the following is most stable ?
Sn2+
Ge2+
Si2+
Pb2+
The metal used for making radiations shield is
Pb
Fe
Zn
Si
In curing cement plasters water is sprinkled from time to time.This helps in
keeping it cool
developing interlocking needle like crystals of hydrated silicates
hydrating sand and gravel mixed with cement
converting sand into silicic acid
Graphite is a soft, solid lubricant,extremely difficult to melt. The reason for this anamolous behaviour is that, graphite
is an allotropic form of diamond
has molecules of variable molecular masses like polymers
has carbon atoms arranged in large plates of rings of strongly bound carbon atoms with weak inter plate bonds
is a non-crystalline substance.
Which one of the following statements regarding helium is incorrect?
It is used to fill gas balloons instead of hydrogen because it is lighter and non inflammable.
It is used as a cryogenic agent for carrying out experiment at low temperature.
It is used to produce and sustain powerful superconducting magnets.
It is used in gas cooled nuclear reactors.
Which one of the following is an amphoteric oxide?
Na2O
SO2
B2O3
ZnO
Of the following compounds, the most acidic is
AS2O3
P2O5
Sb2O3
Bi2O3
For making good quality mirrors, plates of flint glass are used. These are obtained by floating molten glass over a liquid metal which does not solidify before glass. The metal used can be
Tin
Sodium
Magnesium
Mercury