Nitrogen shows different oxidation states in the range
0 to +5
-3 to +5
-5 to +3
-3 to +3
Which one of the following is an amphoteric oxide?
Na2O
SO2
B2O3
ZnO
When concentrated HNO3 is heated with P2O5, it forms
N2O
NO
NO2
N2O5
PH3, the hydride of phosphorus is
metallic
ionic
non-metallic
covalent
Carborundum is obtained when silica is heated at high temperature with
carbon
carbon monoxide
carbon dioxide
calcium carbonate
The metal used for making radiations shield is
Pb
Fe
Zn
Si
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
Which of the following is a component of ruby?
CaCO3
MgCO3
Al2O3
Al(OH)3
In the alumino-thermite process, Al acts as
Flux
Oxidizing agent
Reducing agent
Promoter
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.
