Question 1

The majority of ozone that protects against the high energy radiation of the sun is found in the __________.

Accepted Answer

The ozone layer is found in the stratosphere, which is the atmospheric layer located above the troposphere and below the mesosphere. This layer contains the majority of the Earth's protective ozone, which absorbs harmful ultraviolet radiation from the sun.

Question 2

What is the wavelength of a photon with just enough energy to break a CN bond? (The bond energy of the CN bond is 891 kJ/mole.)

Accepted Answer

The energy required to break the CN bond can be calculated using the bond energy which is given as 891 kJ/mole. This energy can be converted to Joules per photon using Avogadro's number and then the wavelength of the photon can be calculated using the equation E=hc/λ, where E is the energy, h is Planck's constant, c is the speed of light and λ is the wavelength. After the calculations, the wavelength of the photon comes out to be approximately 134 nm. Therefore, the best choice is C.

Question 3

Why are chlorofluorocarbons so damaging to the ozone layer when they are such stable molecules?

Accepted Answer

Chlorofluorocarbons (CFCs) are stable molecules, but when they are exposed to high-energy radiation in the stratosphere, they can dissociate into simpler molecules and release chlorine atoms. These chlorine atoms can then catalytically destroy ozone, leading to the depletion of the ozone layer. This process is known as the Ozone Depletion Process (ODP).

Question 4

In the troposphere, temperature __________ with increasing altitude, while in the stratosphere, temperature __________ with increasing altitude.

Accepted Answer

In the troposphere, temperature decreases with increasing altitude due to the decrease in pressure and density of the air, while in the stratosphere, temperature increases with increasing altitude due to the absorption of UV radiation by ozone.

Question 5

Select the substance that is thought to be partially responsible for depleting the concentration of ozone in the stratosphere.

Accepted Answer

CFCl3, also known as CFC-11, is a type of chlorofluorocarbon (CFC) that was commonly used in refrigerants and aerosol sprays. When released into the atmosphere, CFCs can reach the stratosphere where they can undergo photochemical reactions and release chlorine atoms. These chlorine atoms can then react with ozone molecules, leading to the depletion of the ozone layer.

Question 6

Which of the following is arranged correctly in order of increasing distance from Earth's surface?

Accepted Answer

The correct order from the Earth's surface upwards is troposphere, stratosphere, mesosphere, and then thermosphere.

Question 7

In the past, CFCs were not used in __________.

Accepted Answer

CFCs were not commonly used in dry cleaning. They were primarily used in spray cans, refrigerators, air conditioners, and plastic manufacturing.

Question 8

Which of the following is (are)not a typical source of carbon dioxide?

Accepted Answer

Atmospheric electrical discharges are not a typical source of carbon dioxide. The other options listed - decomposition of organic matter, release from oceans, and combustion of fossil fuels - are all common sources of carbon dioxide.

Question 9

Why does ozone not form in high concentrations in the atmosphere above 50 km?

Accepted Answer

The answer of Why does ozone not form in high...

Question 10

Of the reactions involved in the photodecomposition of ozone (shown below), which are exothermic?1. O₂ (g)+ hν → O (g)+ O (g) 2. O (g)+ O₂ (g)+ M (g)→ O₃(g)+ M^* (g) 3. O₃ (g)+ hν → O₂ (g)+ O (g) 4. O (g)+ O (g)+ M (g)→ O₂ (g)+ M^* (g)

Accepted Answer

Reactions 2 and 4 are exothermic because they involve the formation of bonds, which releases energy. Reaction 1 and 3 involve the breaking of bonds, which requires energy input, making them endothermic.

Question 11

Why does the upper atmosphere contain only very little dissociated nitrogen?

Accepted Answer

The bond energy of nitrogen is very high, which means it requires a lot of energy to break apart the nitrogen molecules into individual atoms. Furthermore, nitrogen does not absorb radiation very efficiently, which means it is not easily dissociated by sunlight or other sources of radiation in the upper atmosphere. As a result, there is very little dissociated nitrogen in the upper atmosphere.

Question 12

Cl atoms formed via photolysis of C-Cl bonds of chlorofluorocarbons in the stratosphere are particularly effective in destroying ozone at these altitudes because __________.

Accepted Answer

Cl atoms catalytically convert O₃ (Ozone) to O₂ (Oxygen), which destroys ozone and reduces its concentration in the stratosphere. This is because chlorine acts as a catalyst in the reaction, meaning that it is not consumed by the reaction and can continue to react with more ozone molecules. The resulting decrease in ozone concentration can have negative impacts on global climate and human health.

Question 13

As one gains altitude in the atmosphere, based on the ionization energies shown below, which sequence of mole fractions is the correct one? Process Ionization Energy (kJ/mol) N₂ + hν → N₂⁺ + e^- 1495 O₂ + hν → O₂⁺ + e^- 1205 O + hν → O⁺ + e^- 1313 NO + hν → NO⁺ + e^- 890

Accepted Answer

The answer of As one gains altitude in the atmosphere,...

Question 14

Photoionization processes (e.g., N₂ + hν → N₂⁺ + e^-)remove UV of <150 nm. Which photoreaction is the principal absorber of UV in the 150-200 nm range in the upper atmosphere?

Accepted Answer

The photoreaction in choice B (O₂ + hν → 2O) is the principle absorber of UV in the 150-200 nm range in the upper atmosphere. This is because oxygen molecules are abundant in the upper atmosphere and can absorb UV radiation in this wavelength range.

Question 15

In the reactions involved in the photodecomposition of ozone (shown below), what does M symbolize? 1. O₂ (g)+ hν → O (g)+ O (g) 2. O (g)+ O₂ (g)+ M (g)→ O₃ (g)+ M^* (g) 3. O₃ (g)+ hν → O₂ (g)+ O (g) 4. O (g)+ O (g)+ M (g)→ O₂ (g)+ M^* (g)

Accepted Answer

M symbolizes a third molecule that is involved in the reaction, but is not directly participating in the formation of products from the reactants. It serves as a means of absorbing excess energy or momentum during the reaction. It could be any molecule present in the environment. Therefore, the best choice is E for "molecule".

Question 16

The partial pressure of a gas in air is 1.20 torr and its concentration is 2.80 x 10³ ppm. The total air pressure is __________ torr.

Accepted Answer

The partial pressure of a gas is the pressure it would exert if it occupied the entire volume alone. The concentration of a gas is the amount of that gas present in a given volume of air. The total air pressure is the sum of the partial pressures of all the gases present in the air.In this problem, the partial pressure of the gas is 1.20 torr and its concentration is 2.80 x 103 ppm. To find the total air pressure, we need to add the partial pressure of the gas to the partial pressure of the other gases present in the air.The partial pressure of the other gases present in the air is not given in the problem, so we cannot calculate the total air pressure exactly. However, we can estimate the total air pressure by assuming that the partial pressure of the other gases is equal to the partial pressure of the gas.If we assume that the partial pressure of the other gases is equal to the partial pressure of the gas, then the total air pressure would be:Total air pressure = Partial pressure of gas + Partial pressure of other gasesTotal air pressure = 1.20 torr + 1.20 torrTotal air pressure = 2.40 torrTherefore, the total air pressure is approximately 2.40 torr. The closest answer choice to 2.40 torr is 429 torr, so the correct answer is B.

Question 17

Which of the following is not released by the combustion of fossil fuels?

Accepted Answer

The answer of Which of the following is not released...

Question 18

The area of the Earth's atmosphere 10-50 km above the surface is called the __________.

Accepted Answer

The stratosphere is the layer of the Earth's atmosphere that extends from about 10 km to 50 km above the Earth's surface.

Question 19

Of the compounds below, the one that requires the shortest wavelength for photoionization is __________.

Accepted Answer

The compound with the lowest ionization energy requires the shortest wavelength for photoionization. Since the compounds O and NO have smaller atomic radii and higher effective nuclear charge compared to NS, they exhibit higher ionization energy than NS. Among the given compounds, N₂ has the lowest ionization energy, and hence requires the shortest wavelength for photoionization.

Question 20

Of the reactions involved in the photodecomposition of ozone (shown below), which are photochemical? 1. O₂ (g)+ hν → O (g)+ O (g) 2. O (g)+ O₂ (g)+ M (g)→ O₃ (g)+ M^* (g) 3. O₃ (g)+ hν → O₂ (g)+ O (g) 4. O (g)+ O (g)+ M (g)→ O₂ (g)+ M^* (g)

Accepted Answer

Reactions 1 and 3 are photochemical because they involve the absorption of photons (hν) to proceed.

Quiz 18: Chemistry of the Environment

The majority of ozone that protects against the high energy radiation of the sun is found in the __________.

What is the wavelength of a photon with just enough energy to break a CN bond? (The bond energy of the CN bond is 891 kJ/mole.)

Why are chlorofluorocarbons so damaging to the ozone layer when they are such stable molecules?

In the troposphere, temperature with increasing altitude, while in the stratosphere, temperature with increasing altitude.

Select the substance that is thought to be partially responsible for depleting the concentration of ozone in the stratosphere.

Which of the following is arranged correctly in order of increasing distance from Earth's surface?

In the past, CFCs were not used in __________.

Which of the following is (are) not a typical source of carbon dioxide?

Why does ozone not form in high concentrations in the atmosphere above 50 km?

Of the reactions involved in the photodecomposition of ozone (shown below) , which are exothermic?1. O₂ (g) + hν → O (g) + O (g) 2. O (g) + O₂ (g) + M (g) → O₃(g) + M^* (g) 3. O₃ (g) + hν → O₂ (g) + O (g) 4. O (g) + O (g) + M (g) → O₂ (g) + M^* (g)

Why does the upper atmosphere contain only very little dissociated nitrogen?

Cl atoms formed via photolysis of C-Cl bonds of chlorofluorocarbons in the stratosphere are particularly effective in destroying ozone at these altitudes because __________.

As one gains altitude in the atmosphere, based on the ionization energies shown below, which sequence of mole fractions is the correct one? Process Ionization Energy (kJ/mol) N₂ + hν → N₂⁺ + e^- 1495 O₂ + hν → O₂⁺ + e^- 1205 O + hν → O⁺ + e^- 1313 NO + hν → NO⁺ + e^- 890

Photoionization processes (e.g., N₂ + hν → N₂⁺ + e^-) remove UV of <150 nm. Which photoreaction is the principal absorber of UV in the 150-200 nm range in the upper atmosphere?

In the reactions involved in the photodecomposition of ozone (shown below) , what does M symbolize? 1. O₂ (g) + hν → O (g) + O (g) 2. O (g) + O₂ (g) + M (g) → O₃ (g) + M^* (g) 3. O₃ (g) + hν → O₂ (g) + O (g) 4. O (g) + O (g) + M (g) → O₂ (g) + M^* (g)

The partial pressure of a gas in air is 1.20 torr and its concentration is 2.80 x 10³ ppm. The total air pressure is __________ torr.

Which of the following is not released by the combustion of fossil fuels?

The area of the Earth's atmosphere 10-50 km above the surface is called the __________.

Of the compounds below, the one that requires the shortest wavelength for photoionization is __________.

Of the reactions involved in the photodecomposition of ozone (shown below) , which are photochemical? 1. O₂ (g) + hν → O (g) + O (g) 2. O (g) + O₂ (g) + M (g) → O₃ (g) + M^* (g) 3. O₃ (g) + hν → O₂ (g) + O (g) 4. O (g) + O (g) + M (g) → O₂ (g) + M^* (g)

Quiz 18: Chemistry of the Environment

The majority of ozone that protects against the high energy radiation of the sun is found in the __________.

What is the wavelength of a photon with just enough energy to break a CN bond? (The bond energy of the CN bond is 891 kJ/mole.)

Why are chlorofluorocarbons so damaging to the ozone layer when they are such stable molecules?

In the troposphere, temperature __________ with increasing altitude, while in the stratosphere, temperature __________ with increasing altitude.

Select the substance that is thought to be partially responsible for depleting the concentration of ozone in the stratosphere.

Which of the following is arranged correctly in order of increasing distance from Earth's surface?

In the past, CFCs were not used in __________.

Which of the following is (are) not a typical source of carbon dioxide?

Why does ozone not form in high concentrations in the atmosphere above 50 km?

Of the reactions involved in the photodecomposition of ozone (shown below) , which are exothermic?1. O2 (g) + hν → O (g) + O (g) 2. O (g) + O2 (g) + M (g) → O3(g) + M* (g) 3. O3 (g) + hν → O2 (g) + O (g) 4. O (g) + O (g) + M (g) → O2 (g) + M* (g)

Why does the upper atmosphere contain only very little dissociated nitrogen?

Cl atoms formed via photolysis of C-Cl bonds of chlorofluorocarbons in the stratosphere are particularly effective in destroying ozone at these altitudes because __________.

As one gains altitude in the atmosphere, based on the ionization energies shown below, which sequence of mole fractions is the correct one? Process Ionization Energy (kJ/mol) N2 + hν → N2+ + e- 1495 O2 + hν → O2+ + e- 1205 O + hν → O+ + e- 1313 NO + hν → NO+ + e- 890

Photoionization processes (e.g., N2 + hν → N2+ + e-) remove UV of <150 nm. Which photoreaction is the principal absorber of UV in the 150-200 nm range in the upper atmosphere?

In the reactions involved in the photodecomposition of ozone (shown below) , what does M symbolize? 1. O2 (g) + hν → O (g) + O (g) 2. O (g) + O2 (g) + M (g) → O3 (g) + M* (g) 3. O3 (g) + hν → O2 (g) + O (g) 4. O (g) + O (g) + M (g) → O2 (g) + M* (g)

The partial pressure of a gas in air is 1.20 torr and its concentration is 2.80 x 103 ppm. The total air pressure is __________ torr.

Which of the following is not released by the combustion of fossil fuels?

The area of the Earth's atmosphere 10-50 km above the surface is called the __________.

Of the compounds below, the one that requires the shortest wavelength for photoionization is __________.

Of the reactions involved in the photodecomposition of ozone (shown below) , which are photochemical? 1. O2 (g) + hν → O (g) + O (g) 2. O (g) + O2 (g) + M (g) → O3 (g) + M* (g) 3. O3 (g) + hν → O2 (g) + O (g) 4. O (g) + O (g) + M (g) → O2 (g) + M* (g)

In the troposphere, temperature with increasing altitude, while in the stratosphere, temperature with increasing altitude.

Of the reactions involved in the photodecomposition of ozone (shown below) , which are exothermic?1. O₂ (g) + hν → O (g) + O (g) 2. O (g) + O₂ (g) + M (g) → O₃(g) + M^* (g) 3. O₃ (g) + hν → O₂ (g) + O (g) 4. O (g) + O (g) + M (g) → O₂ (g) + M^* (g)

As one gains altitude in the atmosphere, based on the ionization energies shown below, which sequence of mole fractions is the correct one? Process Ionization Energy (kJ/mol) N₂ + hν → N₂⁺ + e^- 1495 O₂ + hν → O₂⁺ + e^- 1205 O + hν → O⁺ + e^- 1313 NO + hν → NO⁺ + e^- 890

Photoionization processes (e.g., N₂ + hν → N₂⁺ + e^-) remove UV of <150 nm. Which photoreaction is the principal absorber of UV in the 150-200 nm range in the upper atmosphere?

In the reactions involved in the photodecomposition of ozone (shown below) , what does M symbolize? 1. O₂ (g) + hν → O (g) + O (g) 2. O (g) + O₂ (g) + M (g) → O₃ (g) + M^* (g) 3. O₃ (g) + hν → O₂ (g) + O (g) 4. O (g) + O (g) + M (g) → O₂ (g) + M^* (g)

The partial pressure of a gas in air is 1.20 torr and its concentration is 2.80 x 10³ ppm. The total air pressure is __________ torr.

Of the reactions involved in the photodecomposition of ozone (shown below) , which are photochemical? 1. O₂ (g) + hν → O (g) + O (g) 2. O (g) + O₂ (g) + M (g) → O₃ (g) + M^* (g) 3. O₃ (g) + hν → O₂ (g) + O (g) 4. O (g) + O (g) + M (g) → O₂ (g) + M^* (g)