/*! 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 38 Chloromethane, \(\mathrm{CH}_{3}... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 4: Problem 38

Chloromethane, \(\mathrm{CH}_{3} \mathrm{Cl}\), arises from microbial fermentation and is found throughout the environment. It is also produced industrially and is used in the manufacture of various chemicals and has been used as a topical anesthetic. Calculate how much energy is required to convert \(92.5 \mathrm{~g}\) liquid to a vapor at its boiling point, \(-24.09^{\circ} \mathrm{C}\). (The heat of vaporization of \(\mathrm{CH}_{3} \mathrm{Cl}\) is \(21.40 \mathrm{~kJ} / \mathrm{mol}\).)

Short Answer

Expert verified
The energy required is 39.2 kJ.

Step by step solution

01

Calculate moles of Chloromethane

First, determine the molar mass of chloromethane (\(\text{CH}_3 \text{Cl}\)). The atomic masses are: C = 12.01 \(\text{g/mol}\), H = 1.01 \(\text{g/mol}\), and Cl = 35.45 \(\text{g/mol}\). Adding these gives the molar mass: \(12.01 + (3\times 1.01) + 35.45 = 50.49\ \text{g/mol}\). Now, calculate the moles of \(92.5\ \text{g}\) of \(\text{CH}_3 \text{Cl}\) by \(\text{moles} = \frac{\text{mass}}{\text{molar mass}} = \frac{92.5}{50.49} \approx 1.832\ \text{mol}\).
02

Apply heat of vaporization

Now, use the heat of vaporization to find the energy required to vaporize the given mass of chloromethane. The formula for energy is \( \text{energy} = \text{moles} \times \text{heat of vaporization} \). Plug in the values: \(1.832\ \text{mol} \times 21.40\ \text{kJ/mol}\ = 39.1928\ \text{kJ}\).
03

Round off the answer

Finally, provide the energy required by rounding to a suitable number of significant figures. Given that the significant figures in the problem (92.5 and 21.40) suggest three significant figures, the energy required is approximately \(39.2\ \text{kJ}\).

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!

Key Concepts

These are the key concepts you need to understand to accurately answer the question.

Chloromethane
Chloromethane, also known as methyl chloride, is a chemical compound with the formula \(\text{CH}_3\text{Cl}\). It is a colorless, flammable gas with a faint sweet odor. Chloromethane occurs naturally, being released by some types of plankton, fungi, and other plants, and is also produced through microbial fermentation in the environment. Industrially, it is synthesized and used in the production of various chemicals.In addition to its uses in manufacturing, chloromethane has applications as a local anesthetic. Characteristics such as its molecular structure, consisting of one carbon bonded to three hydrogen atoms and a chlorine atom, contribute to its chemical properties and the way it interacts with other substances. The relatively low molar mass of chloromethane makes it efficient to transport when used industrially.
Boiling Point
The boiling point of a substance is the temperature at which its liquid form turns into vapor. For chloromethane, this temperature is exceptionally low, at \(-24.09^{\circ} \mathrm{C}\). This means that chloromethane transitions from liquid to gas at temperatures well below freezing, indicating it has weak intermolecular forces compared to other substances that require higher temperatures to boil.Boiling points give insight into a substance's volatility. Substances like chloromethane with low boiling points are quite volatile and can easily evaporate when exposed to air at room temperature. When considering industrial applications, this property must be considered in storage and handling protocols to prevent unwanted losses through evaporation or accidental releases.
Energy Calculation
The energy calculation for vaporizing chloromethane involves understanding the concept of heat of vaporization. This is the amount of heat energy required to turn one mole of a liquid into vapor without changing its temperature. For chloromethane, this is \(21.40 \mathrm{~kJ/mol}\).To find out how much total energy is needed to vaporize a given mass of chloromethane, you first convert the mass into moles. This conversion requires knowing the molar mass, which for chloromethane is \(50.49\ \text{g/mol}\). By dividing the sample mass by the molar mass, you determine the number of moles.Once you have the number of moles, you multiply it by the heat of vaporization to get the total energy. For \(92.5\ \text{g}\) of chloromethane, this procedure results in approximately \(39.2\ \text{kJ}\) of energy needed, illustrating how much energy is involved in transformations at the molecular level.

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

You hold a gram of copper in one hand and a gram of aluminum in the other. Each metal was originally at \(0{ }^{\circ} \mathrm{C}\). (Both metals are in the shape of a little ball that fits into your hand.) If energy is transferred to both at the same rate, which will warm to your body temperature first? Explain your answer.

What is the value of the standard formation enthalpy for any element under standard conditions?

Criticize each of these statements: (a) Formation enthalpy refers to a reaction in which \(1 \mathrm{~mol}\) of one or more reactants produces some quantity of product. (b) The standard formation enthalpy of \(\mathrm{O}_{2}\) as a gas at \(25^{\circ} \mathrm{C}\) and a pressure of 1 atm is \(15.0 \mathrm{~kJ} / \mathrm{mol}\).

In their home laboratory, two students do an experiment (a rather dangerous one-don't try it without proper safety precautions!) with drain cleaner (Drano, a solid) and toilet bowl cleaner (The Works, a liquid solution). The students measure 1 teaspoon (tsp) of Drano into each of four Styrofoam coffee cups and dissolve the solid in half a cup of water. Then they wash their hands and go have lunch. When they return, they measure the temperature of the solution in each of the four cups and find it to be \(22.3^{\circ} \mathrm{C}\). Next they measure into separate small empty cups \(1,2,3,\) and 4 tablespoons (Tbsp) of The Works. In each cup they add enough water to make the total volume 4 Tbsp. After a few minutes they measure the temperature of each cup and find it to be \(22.3^{\circ} \mathrm{C}\). Finally the two students take each cup of The Works, pour it into a cup of Drano solution, and measure the temperature over a period of a few minutes. Their results are reported in the table. $$ \begin{array}{ccc} \hline & \text { Volume of } & \text { Highest } \\ \text { Experiment } & \text { The Works (Tbsp) } & \text { Temperature ( } \left.{ }^{\circ} \mathrm{C}\right) \\ \hline 1 & 1 & 28.0 \\ 2 & 2 & 33.6 \\ 3 & 3 & 39.3 \\ 4 & 4 & 39.4 \\ \hline \end{array} $$ Discuss these results and interpret them in terms of the thermochemistry and stoichiometry of the reaction. Is the reaction exothermic or endothermic? Why is more energy transferred in some cases than others? For each experiment, which reactant, Drano or The Works, is limiting? Why are the final temperatures nearly the same in experiments 3 and \(4 ?\) What can you conclude about the stoichiometric ratio between the two reactants?

A chemical reaction occurs, and \(20.7 \mathrm{~J}\) is transferred from the chemical system to its surroundings. (Assume that no work is done.) (a) What is the algebraic sign of \(\Delta T_{\text {surroundings }} ?\) (b) What is the algebraic sign of \(\Delta_{r} E_{\text {system }}\) ?
See all solutions

Recommended explanations on Chemistry Textbooks

Making Measurements

Read Explanation

Inorganic Chemistry

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Physical Chemistry

Read Explanation

Organic Chemistry

Read Explanation

Chemical Analysis

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.