What possible impurities does rain water contain?

Hint: Rainwater is considered to be the mixed electrolyte which contains both major and minor ions. It is considered to be soft water because it has not collected soluble matter from the soil. Rainwater has an alkaline pH which therefore neutralizes the pH of blood and makes the functioning of the body smooth.


Complete solution:
 Rainwater is considered to be a homogeneous mixture. It has the particles in it which cannot be further filtered out. It contains impurities with it such as dust which is present in the atmosphere. It contains dissolved oxygen, nitrogen and other gases like carbon dioxide as impurities in it. The rainwater comes through the process of condensation of water droplets. The water which is present in the sea, river and ocean get evaporated during the presence of sun by sunlight by the process of vaporization. Rainwater is considered as the natural distilled water which contains no minerals in it and no ions. Although rainwater contains impurities like gases but still it is stored or harvested for use. Rainwater harvesting is the process or technology which is used to collect or store water from roof tops, parks or open ground. The process includes catchment, in this process the water is captured then comes the conveyance system, during which the harvested water is transported to the recharge zone. Then it is flushed, filtered and at last stored to tanks.


Note: The rain water harvesting is a process of benefits as it has less cost and helps in reducing water bills. It does not require any filtration for landscape irrigation. It is simple to install and reduces erosion of soil, stormwater runoff. It promotes water conservation and energy conservation.