Photochemical Smog Results When


Photochemical Smog Results When?

Photochemical smog is a type of smog produced when ultraviolet light from the sun reacts with nitrogen oxides in the atmosphere. It is visible as a brown haze and is most prominent during the morning and afternoon especially in densely populated warm cities.Sep 3 2018

What is photochemical smog a result of?

What is photochemical smog? Photochemical smog is a mixture of pollutants that are formed when nitrogen oxides and volatile organic compounds (VOCs) react to sunlight creating a brown haze above cities. It tends to occur more often in summer because that is when we have the most sunlight.

What is photochemical smog how is it formed and how does it effect?

Photochemical smog refers to a type of smog which is formed when the ultraviolet light from the sun reacts with nitrogen oxides present in the atmosphere. This smog can cause a lot of adverse effects on humans and other living organisms.

How is photochemical smog produced?

Photochemical smog is produced when sunlight reacts with nitrogen oxides and at least one volatile organic compound (VOC) in the atmosphere. Nitrogen oxides come from car exhaust coal power plants and factory emissions. VOCs are released from gasoline paints and many cleaning solvents.

Where does photochemical smog occur?

Photochemical smog which is also known as “Los Angeles smog ” occurs most prominently in urban areas that have large numbers of automobiles. It requires neither smoke nor fog. This type of smog has its origin in the nitrogen oxides and hydrocarbon vapours emitted by automobiles…

See also what do you call a person from the bahamas

Why is La prone to photochemical smog?

How Does Smog Form? … The smog in London was caused by soot and other air pollutants that form during combustion of fuels such as coal. In Los Angeles smog is caused by a set of chemical reactions that require sunlight. When the Sun plays a role in chemical reactions the reactions are called photochemical reactions.

What is the difference between photochemical smog and industrial smog?

It is produced when nitrogen oxides and volatile organic compounds in automobile and fossil-fueled power-plant emissions combine with oxygen in the air in direct sunlight. Whereas industrial smog casts a gray pallor over the areas it affects the nitrogen dioxide in photochemical smog creates a dingy brownish haze.

What are the effects of photochemical smog How can photochemical smog be controlled?


Photochemical smog is obtained from the burning of fossil fuels and automobile fuels that emit NO2 and hydrocarbons which in turn form ozone PAN and other chemicals. To prevent the release of NO2 and hydrocarbons into the atmosphere the use of catalytic converters in automobiles is recommended.

What causes photochemical smog quizlet?

Photochemical smog is caused by nitrogen oxides combing with sunlight and other pollutants. Acid rain is caused by sulfur oxides and nitrogen oxides combining with water. You just studied 13 terms!

Is photochemical smog a secondary pollutant?

Secondary pollutants are pollutants which form in the atmosphere. These pollutants are not emitted directly from a source (like vehicles or power plants). … Photochemical smog is made up of various secondary pollutants like ozone peroxyacyl nitrates (PANs) and nitric acid (seen in Figure 2).

How is ozone formed in photochemical smog?

VOCs + NOx = Ozone. These volatile organic compounds react to form ozone only in the presence of sunlight. … This blue light is producing the UV light that is required to create ozone. And this ozone again reacts with volatile organic compounds to produce photochemical smog.

What is photochemical smog list the factors that favor the formation of photochemical smog?

Photochemical smog development factors

1-Nitrogen source and released organic combinations combining high density of this material with industrializing and transportation are important factors forming photochemical smog. These factors cause some pollution to form in atmosphere by combustion fossil fuel.

Is photochemical smog a primary pollutant?

Photochemical smog is composed of primary and secondary pollutants. Primary pollutants which include nitrogen oxides and volatile organic compounds are introduced into the atmosphere via vehicular emissions and industrial processes. … Photochemical smog is most common in sunny and dry cities like Los Angeles.

What is the main component of photochemical smog?

The major undesirable components of photochemical smog are nitrogen dioxide (NO2) ozone (O3) PAN (peroxyacetylnitrate) and chemical compounds that contain the –CHO group (aldehydes). PAN and aldehydes can cause eye irritation and plant damage if their concentrations are sufficiently high.

See also what is state province region mean

Which is present in photochemical smog?

Among the pollutants involved in photochemical smogs are ozone nitrogen dioxide and peroxyacyl nitrate (PAN). The nitrogen dioxide and other oxides of nitrogen are primary pollutants produced by dissociation in combustion reactions and both ‘prompt’ and ‘thermal’ NOx can be involved in the reactions.

Which of the following is responsible for photochemical smog?

Hydrocarbons oxides of nitrogen and carbon monoxide are responsible for photochemical smog.

Why is photochemical smog more apparent in urban areas?

Photochemical smog forms from a complex process however the source of it is quite apparent. … Due to the direct production of it by vehicles the smog forms over cities where many people may encounter its adverse health effects.

When was photochemical smog attacked in Los Angeles?

Gets First Big Smog. 1943: In the middle of World War II Los Angeles residents believe the Japanese are attacking them with chemical warfare. A thick fog that makes people’s eyes sting and their noses run has taken hold of the city.

What is the difference between sulfurous smog and photochemical smog in polluted air?

Sulfurous smog also known as London smog develops due to high concentration of sulfur oxides in the air. … Photochemical smog is produced when sunlight reacts with oxides of nitrogen and at least one volatile organic compound (VOC) in the atmosphere.

Is photochemical and industrial smog?

Both industrial smog and photochemical smog are forms of air pollution. … Photochemical smog occurs in drier sunny areas and forms because of increased usage of all fossil fuels including gasoline and the burning of trees and organic waste.

What is the difference between London type smog and photochemical smog?

As the reaction take place in the presence of light to form the smog it is called photochemical smog.

Classical Smog vs Photochemical Smog.
London smog or Classical smog Los Angeles smog or Photochemical smog
It involves smoke and fog (smog) The word smog is misnomer here as it does not involve any smoke or fog.

Why is photochemical smog typically worse in the summer?

Why is photochemical smog typically worse in the summer? There is more solar energy to drive photochemical reactions. … Reactions occur between secondary air pollutants and sunlight.

What is the effect of photochemical smog on plants?

Ozone and peroxyacetyl nitrate that travel close to the ground as a result of smog can have damaging effects on plants resulting in the discoloration and damage to plants. This reduces the amount of photosynthesis that these plants can engage in according to the University of California.

What are harmful effects of photochemical smog how can they be minimized?

The photochemical smog is prevented by different ways like plantation catalytic converters etc. The harmful effects of smog are: Ozone peroxyacyl nitrates and PAN occur in the eyes and into the respiratory system. Smog has oxidizing nature.

What is the difference between photochemical smog and London type smog quizlet?

What is the difference between photochemical smog and London-type smog? London-style smog was caused by coal that people burned in factories and homes in humid cloudy air. Photochemical smog is found in cities with a lot of sunlight and the is the light particles interacting with the pollution.

What causes smog and acid rain?

The pollutants in smog come from vehicle emissions smokestack emissions paints and solvents – most of which started out as crude oil. … The pollutants of acid rain are derived from coal fired power plants.

Do you think that photochemical smog levels are higher during the winter or during the summer?

since photochemical smog is formed from the reaction of sunlight on hydrocarbons and nitrogen oxides photochemical smog levels are higher during the summer when Earth atmosphere absorbs more of the sun’s solar energy.

Which pollutant is the major contributor to photochemical smog?


Option 2 is the correct answer: Ozone is the major contributor to photochemical smog.

See also what is political maps

Why is photochemical smog a secondary pollutant?

An important secondary pollutant for photochemical smog is ozone which is formed when hydrocarbons (HC) and nitrogen oxides (NOx) combine in the presence of sunlight nitrogen dioxide (NO2) which is formed as nitric oxide (NO) combines with oxygen (O2) in the air.

What is photochemical smog in environmental chemistry?

Photochemical smog is a type of air pollution due to the reaction of solar radiation with airborne pollutant mixtures of nitrogen oxides (NOx) and volatile organic compounds (hydrocarbons). Smog is a byproduct of modern industrialization. … Oxidation: Photochemical smog is also referred to as oxidizing smog.

Are photochemical smog and ozone the same?

Photochemical smog consists of ozone (O3) and other closely related species (“secondary pollutants”) that are produced photochemically from directly emitted species in a process that is driven by sunlight and is accelerated by warm temperatures.

Is photochemical smog always contains ozone?

The photochemical smog always contains the Ozone gas or O3 as a pollutant. So the correct answer is “Ozone”. Note: – The presence of ozone is explained by a concept known as the photostationary state.

What are the factors affecting the formation and severity of photochemical smog?

U5 The frequency and severity of smog in an area depends on local topography climate population density and fossil fuel use. Photochemical smog is a mixture of about one hundred primary and secondary pollutants formed under the influence of sunlight. Ozone is the main pollutant.

What is photochemical smog discuss different types of smog?

At least two distinct types of smog are recognized: 1) Sulfurous smog (or ‘London-type’ smog) 2) Photochemical smog (‘Los Angeles-type’ smog). Sulfurous smog results from a high concentration of sulfur oxides in the air and is caused by the use of sulfur-bearing fossil fuels particularly coal.

Photochemical Smog (Animation)

The science of smog – Kim Preshoff

Lecture 3.2 Photochemical Smog


Leave a Comment