Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 21: Problem 23

The molecule tetraborane has the formula \(\mathrm{B}_{4} \mathrm{H}_{10}\) (a) Show that this is an electron-deficient molecule. (b) How many bridge bonds must occur in the molecule? (c) Show that butane, \(\mathrm{C}_{4} \mathrm{H}_{10},\) is not electron deficient.

Short Answer

Expert verified
(a) Tetraborane is electron deficient because it has 22 electrons, enough for only 11 bonds, even though a total of 13 are required. (b) Two 3-center-2-electron bonds must occur in the molecule. (c) Butane is not electron deficient because it has 26 electrons, enough for the 13 bonds required for all atoms.

Step by step solution

01

Determine Electron number for Tetraborane

Tetraborane has 4 boron atoms, each with 3 valence electrons and 10 hydrogen atoms each with a single electron, thus it in total has \(4*3 + 10*1=22\) electrons. This amount should be enough for a total of \(22/2= 11 \) bonds.
02

Compare to Required Bonds

Tetraborane molecule has 14 atoms, and so if each atom were to form a two-electron bond, they would require a total of \(14-1= 13 \) bonds. As calculated in step 1, only 11 bonds worth of electrons are available. Hence, tetraborane is electron deficient.
03

Calculate Bridge Bonds

As tetraborane is electron deficient, it must have less 2-center-2-electron bonds and more of 3-center-2-electron or bridge bonds. Given that two 3-center-2-electron bonds replace three 2-center-2-electron bonds, the total number of 3-center-2-electron bonds must be equal to \(13 - 11 = 2\) bonds.
04

Determine Electron number for Butane

Butane carries 4 carbon atoms each providing 4 valence electrons and 10 hydrogen atoms each providing 1 valence electron. Therefore, the total number of electrons in butane is \(4 * 4 + 10 * 1 = 26 \) . This provides \(26/2=13 \) 2-electron bonds.
05

Compare to Required Bonds for Butane

Butane carries 14 atoms and if each atom needs a 2-electron bond, the total number of bonds required is \(14-1= 13 \). Thus butane has enough electrons for each atom to engage in a 2-electron bond, and it is not electron deficient.

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

A chemical dictionary gives the following descriptions of the production of some compounds. Write plausible chemical equations based on these descriptions. (a) lead(II) carbonate: adding a solution of sodium bicarbonate to a solution of lead nitrate. (b) lithium carbonate: reaction of lithium oxide with ammonium carbonate solution. (c) hydrogen peroxide: by the action of dilute sulfuric acid on barium peroxide. (d) lead(IV) oxide: action of an alkaline solution of calcium hypochlorite on lead(II) oxide.

Listed are several pairs of substances. For some pairs, one or both members of the pair react individually with water to produce a gas. For others, neither member of the pair reacts with water. The pair for which each member reacts with water and yields the same gaseous product is (a) \(\mathrm{Al}(\mathrm{s})\) and \(\mathrm{Ba}(\mathrm{s}) ;\) (b) \(\mathrm{Ca}(\mathrm{s})\) and \(\mathrm{CaH}_{2}(\mathrm{s}) ; \quad(\mathrm{c}) \quad \mathrm{Na}(\mathrm{s})\) and \(\mathrm{Na}_{2} \mathrm{O}_{2}(\mathrm{s}) ; \quad\) (d) \(\mathrm{K}(\mathrm{s})\) and \(\mathrm{KO}_{2}(\mathrm{s}) ;(\mathrm{e}) \mathrm{NaHCO}_{3}(\mathrm{s})\) and \(\mathrm{HCl}(\mathrm{aq}).\)

Write plausible chemical equations for the (a) dissolving of lead(II) oxide in nitric acid; (b) heating of \(\operatorname{snCO}_{3}(\mathrm{s}) ;\) (c) reduction of lead(II) oxide by carbon; (d) reduction of \(\mathrm{Fe}^{3+}(\mathrm{aq})\) to \(\mathrm{Fe}^{2+}(\mathrm{aq})\) by \(\mathrm{Sn}^{2+}(\mathrm{aq});\) (e) formation of lead(II) sulfate during high-temperature roasting of lead(II) sulfide.

A description for preparing potassium aluminum alum calls for dissolving aluminum foil in KOH(aq). The solution obtained is treated with \(\mathrm{H}_{2} \mathrm{SO}_{4}(\mathrm{aq}),\) and the alum is crystallized from the resulting solution. Write plausible equations for these reactions.

Describe a series of simple chemical reactions that you could use to determine whether a particular metal sample is "aluminum 2S" (99.2\% Al) or "magnalium" (70\% Al, 30\% Mg). You are permitted to destroy the metal sample in the testing.
See all solutions

Recommended explanations on Chemistry Textbooks

Ionic and Molecular Compounds

Read Explanation

Chemical Reactions

Read Explanation

Making Measurements

Read Explanation

Nuclear Chemistry

Read Explanation

Chemical Analysis

Read Explanation

Physical 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