Question

(a) What is detergent?
(b) Explain the causes of ozone depletion.
(c)Draw a labeled diagram of ‘Khadin water harvesting system’ and write any two measures of water conservation.

Answer 1

Hint: A detergent is a surfactant similar to soap with cleansing properties. It is similar to soap in its structure and also action on the dirty or greasy surfaces. Ozone is a layer of oxygen in the earth atmosphere. It protects life on earth from the harmful effects of UV from the sun. Khadin water harvesting system is a traditional method of collecting rain water.

Complete Step-by-step solution:
(a)Detergent is a surface cleansing agent called a surfactant or it may also contain mixtures of different surfactants. Surfactants are large organic molecules with a long chain of alkyl groups and a metal at the end of the chain. There are different types of detergents such as anionic, cationic, and neutral and zwitter ionic detergents. Most of the commercial detergents are alkyl benzene sulphonates. The action of detergents is by formation of micelles on the oily/greasy substance by the hydrophobic tail part on the dirty surface and the hydrophilic head part into the aqueous medium.
(b)Ozone depletion is one of the major environmental issues being faced these days. Ozone $\left( {{{\text{O}}_{\text{3}}}} \right)$ is a thick layer of oxygen present in the upper atmospheric layers of earth. It plays a vital role in shielding the earth from the harmful effects of the sun's UV rays. Ozone depletion is the thinning of this layer creating ozone holes due to the action of harmful chemicals released from the earth due to human activities. The chemicals responsible for ozone depletion are gases such as Nitric oxide $\left( {{\text{N}}{{\text{O}}_{\text{2}}}} \right)$ and free Chlorine (Cl) atoms from CFCs, HCFCs and halons such as ${\text{ClO,BrO}}$ are also reported to be very effective in ozone depletion. The thinning of ozone layer is very dangerous to entire flora and fauna on the earth and the effective ways in protecting the ozone is minimal usage or decrease of harmful chemical releasing appliances such as air conditioners, refrigerators, chillers, aerosol sprays, automobiles etc.

(C)

Khadin water harvesting system is an indigenous system designated to harvest the rainwater from the surface run off. It is a traditional method of collecting rain water and uses it for agricultural purposes during olden days. Khadin is also called as dhora, it is constructed by digging 100-300mts long earthen embankment across hilly slopes which can collect large amounts of runoff water.

Note: Ozone depletion is one of the major environmental issues being faced these days. Khadin water harvesting system is an indigenous system designated to harvest the rainwater from the surface run off.