/*! 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 4 The molecule shown here is diflu... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 9: Problem 4

The molecule shown here is difluoromethane \(\left(\mathrm{CH}_{2} \mathrm{~F}_{2}\right)\), which is used as a refrigerant called \(R-32\). (a) Based on the structure, how many electron domains surround the \(\mathrm{C}\) atom in this molecule? (b) Would the molecule have a nonzero dipole moment? (c) If the molecule is polar, which of the following describes the direction of the overall dipole moment vector in the molecule: (i) from the carbon atom toward a fluorine atom, (ii) from the carbon atom to a point midway between the fluorine atoms, (iii) from the carbon atom to a point midway between the hydrogen atoms, or (iv) From the carbon atom toward a hydrogen atom? [Sections \(9.2\) and 9.3]

Short Answer

Expert verified
(a) There are 4 electron domains surrounding the carbon atom in difluoromethane (CH2F2). (b) Yes, the molecule has a nonzero dipole moment due to non-cancellation of polar C-F and C-H bonds in the tetrahedral geometry. (c) The direction of the overall dipole moment vector in the molecule is (i) from the carbon atom toward a fluorine atom.

Step by step solution

01

Identify the structure of the molecule

Draw the Lewis structure of difluoromethane (CH2F2). Carbon has 4 valence electrons, hydrogen has 1, and fluorine has 7. C: 1 H-H bond and 2 C-F bonds H: 1 H-C bond F: 1 C-F bond The structure would look like: H | H--C--F | F
02

Determine electron domains surrounding the carbon atom

In order to find the electron domains surrounding the carbon atom, we need to count the bonding and non-bonding electron pairs around the carbon. In the case of CH2F2, carbon has four bonding electron pairs (two with hydrogen and two with fluorine). Therefore, there are 4 electron domains surrounding the carbon atom.
03

Determine if the molecule has a nonzero dipole moment

A nonzero dipole moment occurs when there is an uneven distribution of electron density in a molecule and bonds exhibit polarity, creating a positive and a negative end. In CH2F2, there are polar C-F bonds due to the difference in electronegativity between carbon and fluorine. However, the arrangement of these bonds can either enhance or cancel out the overall dipole moment. Since the molecular geometry is tetrahedral, the dipole vectors of the two C-F bonds and those of the two C-H bonds don't cancel each other out. Hence, the molecule has a nonzero dipole moment.
04

Determine the direction of the overall dipole moment vector

The overall dipole moment vector points toward the more electronegative element in the molecule. In this case, fluorine is the most electronegative element. Here, we have the given options: (i) from the carbon atom toward a fluorine atom (ii) from the carbon atom to a point midway between the fluorine atoms (iii) from the carbon atom to a point midway between the hydrogen atoms (iv) from the carbon atom toward a hydrogen atom Since the dipole moment vector points towards the more electronegative element, the direction of the overall dipole moment vector in the molecule is (i) from the carbon atom toward a fluorine atom.

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.

Electron Domains
In molecular chemistry, electron domains refer to regions around a central atom where electrons are likely to be found. These regions include both bonding electron pairs (shared with neighboring atoms forming a bond) and non-bonding electron pairs (lone pairs).

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

(a) Using only the valence atomic orbitals of a hydrogen atom and a fluorine atom, and following the model of Figure \(9.46\), how many MOs would you expect for the HF molecule? (b) How many of the MOs from part (a) would be occupied by electrons? (c) It turns out that the difference in energies between the valence atomic orbitals of \(\mathrm{H}\) and \(\mathrm{F}\) are sufficiently different that we can neglect the interaction of the \(1 s\) orbital of hydrogen with the \(2 s\) orbital of fluorine. The \(1 s\) orbital of hydrogen will mix only with one \(2 p\) orbital of fluorine. Draw pictures showing the proper orientation of all three \(2 p\) orbitals on \(\mathrm{F}\) interacting with a 1 s orbital on \(\mathrm{H}\). Which of the \(2 p\) orbitals can actually make a bond with a \(1 s\) orbital, assuming that the atoms lie on the \(z\)-axis? (d) In the most accepted picture of HF, all the other atomic orbitals on fluorine move over at the same energy into the molecular orbital energy-level diagram for HF. These are called "nonbonding orbitals." Sketch the energy-level diagram for HF using this information and calculate the bond order. (Nonbonding electrons do not contribute to bond order.) (e) Look at the Lewis structure for HF. Where are the nonbonding electrons?

(a) What is the physical basis for the VSEPR model? (b) When applying the VSEPR model, we count a double or triple bond as a single electron domain. Why is this justified?

In which of these molecules or ions does the presence of nonbonding electron pairs produce an effect on molecular shape? (a) \(\mathrm{SiH}_{4}\), (b) \(\mathrm{PF}_{3}\), (c) \(\mathrm{HBr}\), (d) \(\mathrm{HCN}\), (e) \(\mathrm{SO}_{2}\).

Methyl isocyanate, \(\mathrm{CH}_{3} \mathrm{NCO}\), was made infamous in 1984 when an accidental leakage of this compound from a storage tank in Bhopal, India, resulted in the deaths of about 3,800 people and severe and lasting injury to many thousands more. (a) Draw a Lewis structure for methyl isocyanate. (b) Draw a ball-and-stick model of the structure, including estimates of all the bond angles in the compound. (c) Predict all the bond distances in the molecule. (d) Do you predict that the molecule will have a dipole moment? Explain.

What are the electron-domain and molecular geometries of a molecule that has the following electron domains on its central atom? (a) Three bonding domains and no nonbonding domains, (b) three bonding domains and one nonbonding domain, (c) two bonding domains and two nonbonding domains.
See all solutions

Recommended explanations on Chemistry Textbooks

Kinetics

Read Explanation

Ionic and Molecular Compounds

Read Explanation

Physical Chemistry

Read Explanation

Chemistry Branches

Read Explanation

Organic Chemistry

Read Explanation

Nuclear Chemistry

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.