CHEMISTRY [1 Mark Question Answer]

It is because hard water does not form lather easily with soap.

The process of using ozone gas for disinfection of drinking water is called ozonization. It does not affect the taste or odour of water.

Bleaching powder which releases chlorine in water.

Salts of calcium, magnesium, sodium, etc.

Oceans, seas, rivers, lakes and streams.

Permanent hardness of water is due to the presence of dissolved chlorides and sulphates of calcium and magnesium.

Water has the ability to dissolve many substances to form aqueous solutions. Therefore, it is described as the universal solvent.

Aquatic plants use dissolved Carbon dioxide in water for photosynthesis and aquatic animals use dissolved oxygen in water for respiration.

Density of ice at 0°C is less than the density of water. Therefore, ice floats on the surface of water.

Mixing with potash alum, fine suspended particles become heavy and settle down at the bottom of the loading tank. It increases the rate of sedimentation.

Distilled water is not good for drinking as it tastes flat and lacks dissolved salt and minerals required for our body.

Sea water is not fit for drinking as it contains large amounts of dissolved salts.