Pure And Impure Matter Test - 3

A solute is a substance that is dissolved in another substance. Thus in a mixture of phenol (80%) and water (20%), water is a solute.

Black lead is also known as graphite and it is a form of carbon in which the carbon atoms form layers. Whereas, all other options are examples of compounds.

Red lead is Pb₃O₄, silicon dioxide is also known as silica, and calcium hydroxide is known as slaked lime.

Rust is a mixture of Fe₂O₃ and Fe(OH)₂.

Au is a symbol of gold which is a metal not a metalloid.

When sulphur is mixed with water, it forms a colloid which is a heterogeneous mixture.

Air is a mixture, water is a compound, amalgam is an alloy and iodine vapours is an element.

The chemical symbol 'W' stands for tungsten.

Dry ice is the solid form of carbon dioxide.

The formula for lime water is Ca(OH)₂.

Cooking in an open vessel is slower as compared to cooking in a pressure cooker and, cooking at higher altitudes is slower than at sea level. This is because an increase in the surrounding pressure increases the boiling point of the substance and a higher cooking temper is set up in the cooking vessel.