/*! This file is auto-generated */ .wp-block-button__link{color:#fff;background-color:#32373c;border-radius:9999px;box-shadow:none;text-decoration:none;padding:calc(.667em + 2px) calc(1.333em + 2px);font-size:1.125em}.wp-block-file__button{background:#32373c;color:#fff;text-decoration:none} Problem 23 (a) What is the difference betwe... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 18: Problem 23

(a) What is the difference between chlorofluorocarbons and hydrofluorocarbons? (b) Why are hydrofluorocarbons potentially less harmful to the ozone layer than CFCs?

Short Answer

Expert verified
(a) The main difference between chlorofluorocarbons (CFCs) and hydrofluorocarbons (HFCs) lies in their molecular structure. CFCs are composed of carbon, chlorine, and fluorine atoms, while HFCs contain hydrogen, carbon, and fluorine atoms. The presence of hydrogen atoms in HFCs makes them less stable. (b) HFCs are potentially less harmful to the ozone layer because they do not release chlorine atoms in the stratosphere. Due to their instability, HFCs break down more quickly than CFCs, and since they lack chlorine, HFCs do not contribute to the catalytic destruction of ozone, resulting in a lower ozone depletion potential (ODP) compared to CFCs. However, HFCs are potent greenhouse gases and contribute to global warming.

Step by step solution

01

Defining Chlorofluorocarbons (CFCs)

CFCs are organic compounds made up of carbon, chlorine, and fluorine atoms, with one or more carbon-fluorine bonds. They were widely used as refrigerants, propellants, and solvents, primarily because they are non-toxic, non-flammable, and chemically stable.
02

Defining Hydrofluorocarbons (HFCs)

HFCs are organic compounds containing hydrogen atoms in addition to carbon and fluorine. They were introduced as alternatives to CFCs to reduce ozone depletion. HFCs have similar properties to CFCs, such as being non-toxic, non-flammable, and chemically stable, but with lower ozone depletion potential.
03

Comparing the Molecular Structures

The significant difference between CFCs and HFCs lies in their molecular structure. CFCs have carbon, chlorine, and fluorine atoms, while HFCs have hydrogen, carbon, and fluorine atoms. The presence of hydrogen atoms in HFCs makes them less stable and less harmful to the ozone layer. Part (b): Reasons why HFCs are less harmful to the ozone layer
04

Ozone Depletion Mechanism

CFCs are non-reactive and can last for a long time in the lower atmosphere before rising to the stratosphere, the atmospheric layer containing the ozone. When CFCs reach the stratosphere, they are broken down by ultraviolet (UV) radiation, releasing chlorine atoms. These chlorine atoms react with ozone molecules, catalyzing their breakdown into oxygen molecules and leading to ozone depletion.
05

Instability of HFCs

HFCs are less stable than CFCs due to the presence of hydrogen atoms in their molecular structure. When they reach the stratosphere, HFCs break down more quickly than CFCs and do not release chlorine atoms due to the absence of chlorine in their composition. As a result, HFCs do not contribute to the catalytic destruction of ozone.
06

Lower Ozone Depletion Potential

Since HFCs do not release chlorine atoms in the stratosphere, their ozone depletion potential (ODP) is close to zero. This factor makes HFCs less harmful to the ozone layer than CFCs, whose ODP values are typically greater than zero. Although HFCs have lower ODP, they are potent greenhouse gases, contributing to global warming. In conclusion, HFCs are less harmful to the ozone layer than CFCs mainly because of their molecular structure and instability, which do not lead to the release of chlorine atoms in the stratosphere.

Unlock Step-by-Step Solutions & Ace Your Exams!

  • Full Textbook Solutions

    Get detailed explanations and key concepts

  • Unlimited Al creation

    Al flashcards, explanations, exams and more...

  • Ads-free access

    To over 500 millions flashcards

  • Money-back guarantee

    We refund you if you fail your exam.

Over 30 million students worldwide already upgrade their learning with 91影视!

One App. One Place for Learning.

All the tools & learning materials you need for study success - in one app.

Get started for free

Most popular questions from this chapter

Natural gas consists primarily of methane, \(\mathrm{CH}_{4}(\mathrm{~g})\). (a) Write a balanced chemical equation for the complete combustion of methane to produce \(\mathrm{CO}_{2}(g)\) as the only carbon-containing product. (b) Write a balanced chemical equation for the incomplete combustion of methane to produce \(\mathrm{CO}(\mathrm{g})\) as the only carbon-containing product. (c) At \(25^{\circ} \mathrm{C}\) and \(1.0 \mathrm{~atm}\) pressure, what is the minimum quantity of dry air needed to combust \(1.0 \mathrm{~L}\) of \(\mathrm{CH}_{4}(\mathrm{~g})\) completely to \(\mathrm{CO}_{2}(\mathrm{~g})\) ?

It was estimated that the eruption of the Mount Pinatubo volcano resulted in the injection of 20 million metric tons of \(\mathrm{SO}_{2}\) into the atmosphere. Most of this \(\mathrm{SO}_{2}\) underwent oxidation to \(\mathrm{SO}_{2}\), which reacts with atmospheric water to form an aerosol. (a) Write chemical equations for the processes leading to formation of the aerosol. (b) The aerosols caused a \(0.5-0.6^{\circ} \mathrm{C}\) drop in surface temperature in the northern hemisphere. What is the mechanism by which this occurs? (c) The sulfate aerosols, as they are called, also cause loss of ozone from the stratosphere. How might this occur?

The organic anion CCCCCC(C)c1ccc(S(=O)(=O)[O-])cc1 is found in most detergents. Assume that the anion undergoes aerobic decomposition in the following manner: $2 \mathrm{C}_{18} \mathrm{H}_{2} \mathrm{SO}_{3}^{-}(a q)+51 \mathrm{O}_{2}(a q) \longrightarrow$ $36 \mathrm{CO}_{2}(a q)+28 \mathrm{H}_{2} \mathrm{O}(l)+2 \mathrm{H}^{+}(a q)+2 \mathrm{SO}_{4}^{2-}(a q)$ What is the total mass of \(\mathrm{O}_{2}\) required to biodegrade $10.0 \mathrm{~g}$ of this substance?

(a) Which of the following ionic species could be responsible for hardness in a water supply: \(\mathrm{Ca}^{2+}, \mathrm{K}^{+}, \mathrm{Mg}^{2+}, \mathrm{Fe}^{2+}, \mathrm{Na}^{+}\)? (b) What properties of an ion determine whether it will contribute to water hardness?

One of the principles of green chemistry is that it is better to use as few steps as possible in making new chemicals. In what ways does following this rule advance the goals of green chemistry? How does this principle relate to energy efficiency?
See all solutions

Recommended explanations on Chemistry Textbooks

The Earths Atmosphere

Read Explanation

Physical Chemistry

Read Explanation

Nuclear Chemistry

Read Explanation

Kinetics

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Chemical Reactions

Read Explanation
View all explanations

What do you think about this solution?

We value your feedback to improve our textbook solutions.

Study anywhere. Anytime. Across all devices.