Question

The OH radical is important in the daytime chemistry reactions in the formation of air pollutants.(which one is correct?)

A.it is formed from nitrous acid

B. it reacts with hydrocarbons

C. it is formed from hydrogen peroxide

D it is formed from ozone

E. it is formed only in the early morning hours.

Answer 1

Answer -

The most important oxidizing species is the hydroxyl radical (OH). It is extremely reactive and able to

oxidize most of the chemicals found in the troposphere.

Sources of OH radical are: Ozone, the photolysis of nitrous acid (HONO), hydrogen peroxide (H2O2) or peroxy-methane (CH3OOH).

However OH concentrations are close to zero during the night since sunlight is needed for its formation.

The oxidation of carbon monoxide and methane (hydrocarbon) by OH are very important as they are the major ways by which OH is removed from the atmosphere. Reaction of OH with alkenes (hydrocarbons), a special class of organic compounds, is also very important as this reaction results in the formation of peroxides.

Given,

A.it is formed from nitrous acid

B. it reacts with hydrocarbons

C. it is formed from hydrogen peroxide

D it is formed from ozone

E. it is formed only in the early morning hours.

Therefore from above data you can say that option A, B, C, and D are correct.

Option D is incorrect because OH radical is formed throughout the day in presence of sunlight.