Log out Go to App
Go to App

Learning Materials

Features

Discover

Chapter 26: Problem 43

Draw Newman projections for the staggered and eclipsed conformations of pentane for rotation about the \(\mathrm{C} 2-\mathrm{C} 3\) bond. Which conformation is lowest in energy?

Short Answer

Expert verified
The staggered conformation of pentane is lowest in energy due to the absence of torsional strain, making it more stable than the eclipsed conformation.

Step by step solution

01

Understanding Pentane Structure

Pentane is a linear hydrocarbon with five carbon atoms (\(\mathrm{C}1-\mathrm{C}2-\mathrm{C}3-\mathrm{C}4-\mathrm{C}5\)) and enough hydrogen atoms so that each carbon has four bonds.
02

Drawing Staggered Conformation

Staggered conformation is one where the atoms or groups attached to two adjacent carbon atoms are as far apart as possible. Around \(\mathrm{C}2-\mathrm{C}3\) bond, draw a Newman projection. The three hydrogen atoms connected to \(\mathrm{C}2\) should alternate with the two hydrogen atoms and one \(\mathrm{C}4\) connected to \(\mathrm{C}3\). This represents the staggered conformation of pentane.
03

Drawing Eclipsed Conformation

Eclipsed conformation is one where the atoms or groups attached to two adjacent carbon atoms line up with each other. Similarly, draw a Newman projection around \(\mathrm{C}2-\mathrm{C}3\) bond. The three hydrogen atoms connected to \(\mathrm{C}2\) should align with the two hydrogens and one \(\mathrm{C}4\) to which \(\mathrm{C}3\) is bonded. This shows the eclipsed conformation of pentane.
04

Comparing Energy Levels

Eclipsed conformation is less stable and thus higher in energy due to the torsional strain. The hydrogens that line up with each other can cause close contact between electron clouds, leading them to repel each other. Staggered conformation is more stable and lower in energy as there is no torsional strain, and the electron clouds are as far apart as possible.

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

Give the isomers of the esters having the molecular formula \(\mathrm{C}_{5} \mathrm{H}_{10} \mathrm{O}_{2}\).

Draw the structure for each of the following. (a) \((R)-1\) -bromo-1-chloroethane (b) ( \(E\) )-2-bromo-2-pentene (c) \((Z)-1-\) chloro- 3 -ethyl- 3 -heptene (d) \((R)\) -2-hydroxypropanoic acid (e) ( \(S\) )-2-aminopropanoate anion.

Classify the carbon atoms in (a) methylbutane, and (b) 2,2 -dimethylpropane as methyl, primary \(\left(1^{\circ}\right)\) secondary \(\left(2^{\circ}\right),\) tertiary \(\left(3^{\circ}\right),\) or quaternary \(\left(4^{\circ}\right)\).

In the monochlorination of hydrocarbons, a hydrogen atom is replaced by a chlorine atom. How many different monochloro derivatives of 2 -methylbutane are possible?

Give an acceptable name for each of the following structures. (a) \(\mathrm{CH}_{3} \mathrm{CH}_{2} \mathrm{C}\left(\mathrm{CH}_{3}\right)_{3}\) (b) \(\left(\mathrm{CH}_{3}\right)_{2} \mathrm{C}=\mathrm{CH}_{2}\) (c) \(\mathrm{CH}_{3}-\mathrm{CH}-\mathrm{CH}-\mathrm{CH}_{3}\) \(\mathrm{CH}_{2}\) (d) \(\mathrm{CH}_{3} \mathrm{C} \equiv \mathrm{CCH}\left(\mathrm{CH}_{3}\right)_{2}\) (e) \(\mathrm{CH}_{3} \mathrm{CH}\left(\mathrm{C}_{2} \mathrm{H}_{5}\right) \mathrm{CH}\left(\mathrm{CH}_{3}\right) \mathrm{CH}_{2} \mathrm{CH}_{3}\) (f) \(\mathrm{CH}_{3} \mathrm{CH}\left(\mathrm{CH}_{3}\right) \mathrm{CH}\left(\mathrm{CH}_{3}\right) \mathrm{CCH}_{2} \mathrm{CH}_{2} \mathrm{CH}_{3}=\mathrm{CH}_{2}\)
See all solutions

Recommended explanations on Chemistry Textbooks

Chemistry Branches

Read Explanation

Nuclear Chemistry

Read Explanation

Making Measurements

Read Explanation

Organic Chemistry

Read Explanation

Chemical Reactions

Read Explanation

Kinetics

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