Environmental Chemistry | MCQs

Explanation

The ozone layer protects living things from too much ultraviolet  from entering the atomsphere.

Oxygen layer in the atmosphere

Ozone protects us from the harmful ultraviolet radiation of the sun.

Ozone formula: O3

The ozone layer lies approximately 15-40 kilometers (10-25 miles) above the Earth's surface, in the stratosphere.

The ozone layer is depleting: Air pollution

Explanation

The average global concentration of ozone is around 300 DU,

Meaning if all the ozone in the Earth's atmosphere were compressed to that thickness, it would form a layer 3 millimeters thick. 

Explanation

Green chemistry aims to:

1. Prevent waste creation
2. Maximize atom economy
3. Design safer, less hazardous chemicals and processes

These are all part of the 12 Principles of Green Chemistry outlined by Paul Anastas and John Warner.

Explanation

NO₂ is a reddish-brown gas that gives photochemical smog its characteristic brownish color.

It is formed by the reaction of NO with oxygen in sunlight.

It is a major pollutant in urban smog.

Explanation

The pH of acid rain is less than 5.6. 

Normal rain is slightly acidic due to the dissolution of carbon dioxide from the atmosphere.

It forms weak carbonic acid and typically has a pH of around 5.6

When the pH drops below this value, it is classified as acid rain.

Primarily caused by pollutants like sulfur dioxide and nitrogen oxides, according to the EPA. 

Explanation

A single chlorine-free radical (Cl•) can destroy up to 100,000 ozone (O₃) molecules. This significant impact on ozone is due to the catalytic nature of chlorine in the ozone depletion process.

Explanation

When ultraviolet radiation reacts with chlorofluorocarbons (CFCs), it results in the breakdown of the ozone layer by releasing chlorine radicals Cl° and C° F2Cl.