Question

Match the statement in column A with those in column B

Column 1	Column 2
Well water is generally.	Rainwater
Heat is required to melt 1 g of ice at $0°\mathrm{C}$ to water at $0°\mathrm{C}$	Sp.latent heat of fusion
Purest from of natural water	Potable water
Impure form of water	Water pollution
Maximum density of water at $4°\mathrm{C}$	Sedimentation
The process by which suspended impurities in river water settle down.	1gcm-3
The gas used for killing germs in city water	Cholera
Diseases caused by water pollution.	Chlorine
Washing down excessive pesticides and fertilisers into the river water.	Solution
A product formed by dissolving a solute in solvent.	Seawater

Answer 1

• Well water is generally potable water that is used for household purposes and drinking purposes.
• Heat is required to melt 1 g of ice $0°\mathrm{C}$to water t This process is the latent heat of fusion the heat energy is utilized in changing the state of ice from solid state to liquid state.
• Purest form of natural water- Rainwater is the purest form of naturally occurring free water. because it is formed by the natural distillation of surface water or seawater, by the heat of the sun.
• Impure form of water- Sea water is the largest source of natural water but it is the most impure natural water, as far as the dissolved impurities are concerned.
• Maximum density of water at $4°\mathrm{C}$-Water is the only liquid that does not fall in this category it has been found that 1g of water has a minimum volume of 1cm³ at $4°\mathrm{C}$.thus water has maximum density at$4°\mathrm{C}$.
• The process by which suspended impurities in river water settle down-The process in which river water is pumped into a series of large settling tanks and allowed to stay still for a day when very heavy particles of clay etc settle down at the bottom is called sedimentation.
• The gas used for killing germs in city water-The clear water is chlorinated to remove any harmful bacteria present in it. It is then collected in storage tanks, from where it is distributed.
• Diseases caused by water pollution- If polluted water is consumed by humans or animals it causes diseases like dysentery, diarrhea, jaundice, cholera, typhoid, etc.
• Washing down excessive pesticides and fertilizers into the river water-During agricultural activities farmers use a variety of artificial fertilizers. they spray the crops with very poisonous insecticides which are washed down to the river, thereby causing pollution of potable water.
• A product formed by dissolving a solute in a solvent- The solution is a homogenous mixture of two or more substance's .
• Solution= solute+solvent.