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
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.
The mixture of conc.HCl and HNO3 made 3:1 ratio contains
ClO2
NOCl
NCl3
N2O4
When concentrated HNO3 is heated with P2O5, it forms
N2O
NO
NO2
N2O5
Carborundum is obtained when silica is heated at high temperature with
carbon
carbon monoxide
carbon dioxide
calcium carbonate
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
Which of the following is a component of ruby?
CaCO3
MgCO3
Al2O3
Al(OH)3
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
Which is not a mineral of aluminium?
Anhydrite
Bauxite
Corundum
Diaspore
