The rusting of metal iron in air needs both

• oxygen and moisture

• carbon dioxide and moisture

• water and paint

• water and paint

Acid rain is caused by

• Co and CO

• SO₂ and O₂

• SO₂ and NO₂

• SO₂ and NO₂

Which one of the following is an insulator?

• Copper

• Wood

• Mercury

• Mercury

Zeolite is

• Hydrated ferric oxide

• Hydrated sodium aluminium silicate

• Sodium hexameta phosphate

• Sodium hexameta phosphate

The most extensive use of molasses after fermentation is for producing

• Methanol

• Sugar

• Ethanol

• Ethanol

At boiling points of liquids, its ..............

• Temperature increases

• Atmospheric pressure increases

• Temperature remains constant

• Temperature remains constant

Terylene is a condensation polymer of ethylene glycol and which acid?

• Benzoic Acid

• Salicylic Acid

• Phthalic acid

• Phthalic acid

On a clean glass plate a drop of water spreads to form a thin layer whereas a drop of mercury remains almost spherical because ..............

• Mercury is a metal

• Density of mercury is greater than that of water.

• Cohesion of mercury is greater than its adhesion with glass.

• Cohesion of mercury is greater than its adhesion with glass.

Butter is colloid formed when

• Proteins are dispersed in water

• Water is dispersed in fat

• Fat globules are dispersed in water

• Fat globules are dispersed in water

20.

Charcoal can be made at home by burning

• wood in absence of air

• coal in absence of air

• coal in an insufficient supply of air

• coal in an insufficient supply of air