Which gas was responsible for the Bhopal gas tragedy in $1984$?

$CFCl_3$ is responsible for the decomposition of ozone to oxygen. Which of the following reacts with ozone to form oxygen?

Sulphur dioxide is one of the components of polluted air. $SO_{2}$ is also a major contributor to acid rain. The correct and complete reaction to represent acid rain caused by $SO_{2}$ is ..... .

What are biodegradable and non-biodegradable pollutants?

Match the following:

List-$I$ (Pollutant concentration limit in water)	List-$II$ (Effect)
$A. Pb > 50 \ ppb$	$I. \text{Liver damage}$
$B. SO_4^{2-} > 500 \ ppm$	$II. \text{Laxative effect}$
$C. NO_3^{-} > 50 \ ppm$	$III. \text{Blue baby syndrome}$
$D. F^{-} > 2 \ ppm$	$IV. \text{Brown mottling of teeth}$

The correct answer is

Match the activities given in List-$I$ with the pollution produced in List-$II$.

List-$I$	List-$II$
$(A)$ Burning sulfur-containing waste releases gases into the atmosphere.	$(1)$ Water pollution
$(B)$ Use of carbonates as pesticides	$(2)$ Photochemical smog,damage to plant life,corrosion of buildings,respiratory problems,water pollution.
$(C)$ Using synthetic detergents for washing clothes	$(3)$ Damage to the ozone layer
$(D)$ Releasing smoke from vehicles and factories into the atmosphere.	$(4)$ Neurological disorders in humans.
$(E)$ Using chlorofluorocarbon compounds to clean computer parts.	$(5)$ Classical smog,acid rain,water pollution,respiratory problems,damage to buildings,metal corrosion.