Argon is the third largest constituent of air (followed by N₂ & O₂). Its percentage by volume in air is

A mixture of chlorine & sodium bromide acts as a/an

A. Insecticides

B. Analgesic drug

C. Fire retardant

D. Hydrogenation catalyst

__________ are used as corrosion inhibitor for iron & steel in aqueous solutions.

A. Phosphates

B. Chromates

C. Sulphates

D. Bi-carbonates

Hydrazine (N₂H₄) is used mainly as a/an

A. Explosive

B. Rocket fuel

C. Detergents additive

D. None of these

Common salt is generally not produced commonly by __________ method from brine.

A. Freeze drying

B. Electrolytic

C. Solar evaporation

D. Vacuum evaporation