Chapter 21, Problem 21.18QP

Interpretation Introduction

Interpretation: The effects made by volcanic eruptions towards ozone depletion should be determined.

Concept Introduction:

Volcanic eruptions: The molten rock, that is the layer immediately below the uppermost layer (crust), rises through the cracks in crust due to changes in temperature with evolution of gases like ${\text{N}}_{\text{2}}{\text{,CO}}_{\text{2}}{\text{,H}}_{\text{2}}\text{S}$, water vapor, liquids and solids.

The volcanic eruptions are the primary source for the two-third percent composition present in the air.

Atmosphere: The atmosphere is defined as air that is layer of gases which surrounds the earth due to gravity of earth.

The earth atmosphere consists of layers such as thermosphere, mesosphere, stratosphere and troposphere depending on the temperature and its composition.

Stratosphere:

It is found below the mesosphere layer in which the concentration of ozone and other gases are high. The increasing temperature for this layer with respect to increasing height is due to the presence of high concentration of ozone and other gases in it.

The increased temperature is due to the response of UV radiation from sun and hence ozone is formed due to this reaction and the use of ozone is that it prevents the UV radiation from the sun which is actually harmful.

Acid rain: Rain is considered as acid rain when the concentration of acid is high in rain water that is $\text{pH}$ in rain water becomes too low and the acid rain has harmful effects on the living organism due to increased acid concentration.

Sulphur dioxide is the gas responsible for acid rain formation.

Oxidation: It is type of reaction which involves loss of electrons or removal of hydrogen and addition of oxygen atom.

Reduction: It is also type of reaction in which the electrons gets added or addition of hydrogen and removal of oxygen atom.

The process that leads to acid rain is as follows,

1. 1) Extraction of metal from minerals involves process like roasting, smelting and refining which releases ${\text{SO}}_{\text{2}}$ into atmosphere.
2. 2) Burning of fossil fuels in industries also increases ${\text{SO}}_{\text{2}}$ concentration in atmosphere.
3. 3) Volcanic eruptions are primary reason for the ejection of ${\text{SO}}_{\text{2}}$ into atmosphere.

To determine: The effect of volcanic eruptions.