Question

The acidity of rain can be caused by different means. When we talk about the acidity of rain, we are either talking about.

A)the natural acidity of rain from nitrogen or sulfur oxides or the unnatural acidity of rain from carbon dioxide

or

B) the natural acidity of rain from carbon dioxide or unnatural acid rain from nitrogen or sulfur oxides

Answer 1

Natural CO2 is proudced by respiration and decomposition , which is used by green plants for photosynthesis.

But unnatural CO2 is from vehicles, industries etc . Which causes high CO2 concentration in atmosphere and causes unnatural acid rain due to CO2 .

While nitrogen or sulphur oxides causes natural acid rain .

Acid rain is the phenomenon in which pH of rain water becomes acidic (4-5) due to atmospheric CO2 , SO2 and NO2 gases as ;

CO2 + H2O >>>> H2CO3 (carbonic acid)

SO2 + H2O >>>> H2SO3 ( sulphurous acid )

NO2 + H2O >>>>> HNO3 (nitric acid )

These acids lowers the pH of water from neutral to acidic and thus causes acid rain .

Option (A) is correct .