Question

Which of the following statements is not true about classical smog? (A) Its main components are produced by the action of sunlight on emissions of automobiles. (B) Produced in cold and humid climate (C) It contains compounds of reducing nature (D) It contains smoke, fog and sulphur dioxide

Short answer

All given statements (A, B, C, and D) are true about classical smog. However, there might be an error in the question or options provided, as the exercise asks to find a statement that is not true about classical smog.

Step-by-step solution

Statement (A)

Classical smog is also known as London smog, which was prevalent in London during the mid-20th century. Its main components are produced by the action of sunlight on emissions of automobiles. This statement is correct, as sunlight does play a role in the formation of smog.

Statement (B)

Produced in cold and humid climate: This statement is correct. Classical smog usually occurs in cold and humid climates, particularly during the winter months when there's an excess of coal combustion and vehicle emissions combined with stagnant air conditions.

Statement (C)

It contains compounds of reducing nature: This statement is correct. Classical smog contains reducing compounds, particularly sulfur dioxide (SO2) and particulate matter (e.g. soot) from coal combustion and vehicle emissions. These compounds can react with atmospheric moisture, leading to a corrosive and harmful environment.

Statement (D)

It contains smoke, fog, and sulfur dioxide: This statement is also correct. Classical smog is characterized by a mixture of smoke, fog, and sulfur dioxide. Smoke and sulfur dioxide are typically released from the burning of fossil fuels (such as coal) and vehicle exhaust, while fog forms when there is moisture in the air that becomes trapped in the presence of pollutants. Given the analysis of each statement, we can conclude that all of the four statements are true about classical smog. However, since the exercise asks us to find a statement that is not true about classical smog, we could assume the question or options provided an error.

Key concepts

Environmental Chemistry

Environmental chemistry is an essential discipline within chemistry focusing on the study of chemical processes occurring in the environment. It involves analyzing how environmental pollutants, such as gases, heavy metals, and organic compounds, interact with nature.

Central to this field is the investigation of sources, reactions, transport, effects, and fates of chemical species in the air, soil, and water environments. Additionally, it deals with the effects of human activity on the natural environment. For example, the combustion of fossil fuels has significant impacts on air quality, leading to the formation of smog and other atmospheric pollutants.

Understanding how pollutants like sulfur dioxide and nitrogen oxides are emitted into the atmosphere and their environmental transformations are crucial aspects of environmental chemistry. This knowledge is invaluable in assessing risks to human health and ecosystems and is essential in developing strategies to control, reduce, or prevent pollution.

Smog Formation

Smog formation is a complex process influenced by various factors, including emissions from vehicles and industrial sources, weather conditions, and geography. This atmospheric phenomenon typically occurs when there is a higher concentration of pollutants in the air.

There are two main types of smog: photochemical and classical. Photochemical smog, often associated with modern urban areas, arises when sunlight triggers chemical reactions between various pollutants, such as nitrogen oxides and volatile organic compounds (VOCs), leading to the creation of ozone and other harmful substances.

Classical smog, also known as London smog, tends to form in colder climates and is characterized by a mixture of smoke, fog, and sulfur dioxide. It typically happens during the winter months when the air is stagnant, and there is enough moisture to form fog. This type of smog is associated with the coal burned in fireplaces and power plants, emitting sulfur dioxide and particulates that become suspended in the humid air, creating a dense, visible smog.

Atmospheric Pollution

Atmospheric pollution is one of the most pressing environmental concerns of our time. It refers to the presence of substances in the atmosphere that are harmful to the health of living beings and the environment. Common atmospheric pollutants include particulate matter, volatile organic compounds (VOCs), sulfur dioxide, nitrogen oxides, carbon monoxide, ozone, and lead.

These pollutants can originate from various sources, such as industrial activities, transportation, agricultural practices, and natural events like wildfires and volcanic eruptions. Once in the atmosphere, they can affect air quality, climate change, and can lead to health issues such as respiratory diseases, heart conditions, and even premature death.

Efforts to control atmospheric pollution involve regulations to decrease emissions, promoting cleaner technologies, and increasing public awareness. For students and educators alike, understanding the dynamics of atmospheric pollution is essential for fostering an informed society capable of making sustainable choices and advocating for effective environmental policies.