Is Matter Around Us Pure Test - 2

Tincture of iodine is a solution of iodine in alcohol.

An alloy is a homogeneous mixture of two or more metals. It may also contain a non-metal. Solder is an alloy of lead and tin.

Milk is a colloid and not a suspension.

Since the difference between the boiling points of the two liquids is less than 25 K, they will be separated by fractional distillation.

Solubility of a substance is the maximum amount of solute that can dissolve in a fixed amount of solvent at a given temperature. It remains fixed for a substance at a particular temperature.

Therefore, if 100 g of water can dissolve 66 g of NH₄Cl, then 50 g of water can dissolve 33 g of it.

The separation of rock and diamond is done by mechanical picking because they have different colours.
The different appearance and less abundance of diamond particles in the mixture make hand picking easy and convenient.

Centrifugation involves agitating a given mixture so that the lighter component floats at the surface while the denser component settles at the bottom.
Hence, this method is suitable for separating a mixture in which the components have different densities.

Chromatography is the most suitable technique for separating small quantities of dissolved components which relatively differ in their solubilities.

When a mixture of immiscible liquids is left undisturbed, the components separate out in different layers according to their densities, with the one with the maximum density forming the lowermost layer.

Pure crystals of a salt are extracted by cooling its supersaturated solution. First, a supersaturated solution is prepared by heating a substance as the solubility increases on heating. When this solution is cooled slowly, the pure crystals separate out as the solubility decreases on cooling.