Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 9: Problem 24

Use the localized electron model to describe the bonding in $\mathrm{C}_{2} \mathrm{H}_{2}\( (exists as \)\mathrm{HCCH} )$

Short Answer

Expert verified
Using the localized electron model, the bonding in the \(\mathrm{C}_{2}\mathrm{H}_{2}\) molecule (exists as \(\mathrm{HCCH}\)) consists of a triple bond between the two sp-hybridized carbon atoms (one σ bond and two π bonds), and a single bond between each carbon and hydrogen atom, resulting in a linear molecular geometry.

Step by step solution

01

Determination of the Total Number of Valence Electrons

First, we need to determine the total number of valence electrons in the molecule. Using the periodic table, we find that carbon has four valence electrons and hydrogen has one valence electron each. Since there are two carbon atoms and two hydrogen atoms in the molecule, the total number of valence electrons is: \(2\times4 + 2\times1 = 10\)
02

Drawing The Lewis Structure

Using the localized bonding model, we will first draw the Lewis structure of \(\mathrm{HCCH}\), while attempting to satisfy the octet rule. We will first connect each hydrogen atom to a carbon atom, making a single bond between hydrogen and carbon. With 6 valence electrons remaining, we can create a triple bond between the two carbons, satisfying the octet rule. The Lewis structure will look like this: H-C≡C-H
03

Identifying Bonding and Hybridization Scheme

From the Lewis structure, we can see that the two carbon atoms are connected with a triple bond and the hydrogen atoms are connected to the carbon atoms with single bonds. For each carbon atom, we can see that there is one σ (sigma) bond (C-H bond) and two π (pi) bonds (C≡C bond). Considering the localized electron model, the hybridization scheme can be determined by observing the number of electron domains around the carbon atom. Each carbon in ethyne has two electron domains, so their hybridization scheme is sp.
04

Determining Molecular Geometry

The molecular geometry of the \(\mathrm{HCCH}\) molecule can be determined by considering the hybridization of each carbon atom. As both carbon atoms are sp-hybridized, the molecular geometry will be linear. In conclusion, using the localized electron model, we have determined that the bonding in the \(\mathrm{C}_{2}\mathrm{H}_{2}\) molecule (exists as \(\mathrm{HCCH}\)) consists of a triple bond between the two sp-hybridized carbon atoms, and a single bond between each carbon and hydrogen atom, forming a linear molecular geometry.

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.

Start your free trial

Over 30 million students worldwide already upgrade their learning with Vaia!

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

Cyanamide \(\left(\mathrm{H}_{2} \mathrm{NCN}\right),\) an important industrial chemical, is produced by the following steps: $$ \begin{array}{c}{\mathrm{CaC}_{2}+\mathrm{N}_{2} \longrightarrow \mathrm{CaNCN}+\mathrm{C}} \\ {\mathrm{CaNCN} \stackrel{\mathrm{Acid}}{\longrightarrow} \mathrm{H}_{2} \mathrm{NCN}} \\\ {\mathrm{Cyanamide}}\end{array} $$ Calcium cyanamide (CaNCN) is used as a direct-application fertilizer, weed killer, and cotton defoliant. It is also used to make cyanamide, dicyandiamide, and melamine plastics: a. Write Lewis structures for \(\mathrm{NCN}^{2-}, \mathrm{H}_{2} \mathrm{NCN}\) , dicyandiamide, and melamine, including resonance structures where appropriate. b. Give the hybridization of the C and N atoms in each species. c. How many \(\sigma\) bonds and how many \(\pi\) bonds are in each species? d. Is the ring in melamine planar? e. There are three different \(C-N\) bond distances in dicyandiamide, \(\mathrm{NCNC}\left(\mathrm{NH}_{2}\right)_{2}\) , and the molecule is nonlinear. Of all the resonance structures you drew for this molecule, predict which should be the most important.

What modification to the molecular orbital model was made from the experimental evidence that \(\mathrm{B}_{2}\) is paramagnetic?

Compare and contrast bonding molecular orbitals with antibonding molecular orbitals.

Show how a hydrogen 1\(s\) atomic orbital and a fluorine 2\(p\) atomic orbital overlap to form bonding and antibonding molecular orbitals in the hydrogen fluoride molecule. Are these molecular orbitals \(\sigma\) or \(\pi\) molecular orbitals?

Place the species \(\mathrm{B}_{2}^{+}, \mathrm{B}_{2},\) and \(\mathrm{B}_{2}^{-}\) in order of increasing bond length and increasing bond energy.
See all solutions

Recommended explanations on Chemistry Textbooks

Ionic and Molecular Compounds

Read Explanation

Chemical Reactions

Read Explanation

Chemistry Branches

Read Explanation

Making Measurements

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.

Sign-up for free