Advertisements
Advertisements
Question
Gas A, found in the upper layers of the atmosphere, is a deadly poison but is essential for all living beings. The amount of this gas started declining sharply in the 1980s.
- Identify Gas A. How is it formed at higher levels of the atmosphere?
- Why is it essential for all living beings? State the cause for the depletion of this gas.
Advertisements
Solution
- Gas A is Ozone. Alternatively, accept the formula of the gas. Ozone at the higher levels of the atmosphere is a product of UV radiation acting on oxygen (O2) molecule. The higher energy UV radiations split apart some molecular oxygen (O2) into free oxygen (O) atoms. These atoms then combine with molecular oxygen to form ozone.
Alternatively, accept the following equations with the correct molecular formulae. No mark to be assigned if molecular formulae are not correct, when only the equation is written.
- Ozone shields the surface of the earth / protects living organisms from ultraviolet (UV) radiation released by the sun.
Chlorofluorocarbons (CFCs) which are used as refrigerants / in fire extinguishers lead to depletion of ozone layer.
APPEARS IN
RELATED QUESTIONS
The prime source of chlorofluorocarbons is ______.
Name the group of chemical compounds which damages the ozone layer.
The gas A is used by most of the animals to obtain energy from food by the process of respiration. When A is acted upon by radiation X, it gets converted into another gas B which is an allotrope of A but poisonous when inhaled. B forms a kind of layer C in the upper atmosphere which absorbs radiations X coming from a source Y and prevent them from reaching the earth. Some chemicals Z released from the various devices on the earth are destroying the layer C slowly. In fact, a hole has already been formed in layer C over the area D of the earth.
(a) What are gases (i) A, and (ii) B? Write their molecular formulae.
(b) Name the layer C.
(c) What are (i) X, (ii) Y, and (iii) Z?
(d) Name the area D.
(e) Name any two human ailments which may be caused by X.
What would be the effects on widening of ozone hole?
Explain what is smog. Give its effects.
Explain ozone layer, its depletion and effects of ozone depletion.
The following picture depicts a certain phenomenon
- Name the phenomenon and explain it.
- Enlist the sources that are responsible for the above mentioned phenomenon.
- List out the effects of the above phenomenon on humans.
True or False:
Ozone in the Troposphere is a harmful pollutant.
Ozone is abundant in this layer. Ozone heats this layer as it absorbs from incoming ultraviolet radiation from the sun:
In 1987, an agreement was formulated by the United Nations Environment Programme (UNEP) to freeze the production of “X” to prevent the depletion of “Y”. “X” and “Y” respectively referred to here are ______.
