A hydride of nitrogen which is acidic is
NH3
N2H4
N2H2
N3H
Which is not a mineral of aluminium?
Anhydrite
Bauxite
Corundum
Diaspore
Carbogen is
mixture of O2 + 5 - 10% CO2.
used by pneumonia patient for respiration
used by victims of CO poisoning for respiration
All of the above
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.
Carborundum is obtained when silica is heated at high temperature with
carbon
carbon monoxide
carbon dioxide
calcium carbonate
In the alumino-thermite process, Al acts as
Flux
Oxidizing agent
Reducing agent
Promoter
Nitrogen shows different oxidation states in the range
0 to +5
-3 to +5
-5 to +3
-3 to +3
PH3, the hydride of phosphorus is
metallic
ionic
non-metallic
covalent
Alum is widely used to purify water since
It forms complex with clay particles
It coagulates the mud particles
It exchanges Ca2+ and Mg2+ ions present in hard water
Its sulphate ion is water purifier.
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.
