/*! 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 84 What molecular structural featur... [FREE SOLUTION] | 91影视

91影视

Log out

Learning Materials

Features

Discover

Chapter 12: Problem 84

What molecular structural features cause high-density polyethylene to be denser than low-density polyethylene?

Short Answer

Expert verified
The key molecular structural features causing high-density polyethylene (HDPE) to be denser than low-density polyethylene (LDPE) are the differences in their polymer chain structures. HDPE has a linear molecular structure, resulting in closely packed and well-aligned polymer chains with strong intermolecular forces, leading to a higher density. In contrast, LDPE has a branched molecular structure, causing irregular packing and misaligned polymer chains with weaker intermolecular forces, resulting in a lower density.

Step by step solution

01

Understanding HDPE and LDPE Polymers

High-density polyethylene (HDPE) and low-density polyethylene (LDPE) are both thermoplastic polymers made from the monomer ethylene (C2H4). They have different densities due to the variations in their molecular structures, which is a result of the polymerization process. HDPE has a linear molecular structure, while LDPE has a branched molecular structure.
02

Linear Molecular Structure of HDPE

HDPE is produced using a low-pressure process and contains little to no branching in its molecular structure. This means that the polymer chains are closely packed and aligned, leading to stronger intermolecular forces and crystallinity. As a result, HDPE has a higher density compared to LDPE. The density of HDPE typically ranges between 0.941 to 0.965 g/cm鲁.
03

Branched Molecular Structure of LDPE

LDPE, on the other hand, is produced using a high-pressure process, which results in a highly branched molecular structure. The branching in LDPE leads to irregular packing and alignment of the polymer chains, causing weaker intermolecular forces and lower crystallinity. Consequently, LDPE has a lower density compared to HDPE. The density of LDPE typically ranges between 0.910 to 0.940 g/cm鲁.
04

Summary

The molecular structural features causing high-density polyethylene (HDPE) to be denser than low-density polyethylene (LDPE) lies in the differences in their polymer chain structures: 1. HDPE has a linear molecular structure, leading to closely packed and well-aligned polymer chains with strong intermolecular forces. This results in a higher density. 2. LDPE has a branched molecular structure, leading to irregular packing and misaligned polymer chains with weaker intermolecular forces. This results in a lower density.

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!

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

GaAs and GaP \(\left(E_{\mathrm{g}}=2.26 \mathrm{eV}\right)\) make solid solutions that have the same crystal structure as the parent materials, with As and Prandomly distributed throughout the crystal. \(\mathrm{GaP}_{x}\) As \(_{1-x}\) exists for any value of \(x .\) If we assume that the band gap varies linearly with composition between \(x=0\) and \(x=1,\) estimate the band gap for \(\mathrm{GaP}_{0.5} \mathrm{As}_{0.5} .\) What wavelength of light does this correspond to?

Briefly describe each of the following: (a) elastomer, (b) thermoplastic, (c) thermosetting plastic.

An ester is a compound formed by a condensation reaction between a carboxylic acid and an alcohol. Read the discussion of esters in Section 24.4 and then give an example of a reaction forming an ester. How might this kind of reaction be extended to form a polymer (a polyester)?

What is the minimum number of atoms that could be contained in the unit cell of an element with a face-centered cubic lattice?

Hydrogen bonding between polyamide chains plays an important role in determining the properties of a nylon such as nylon 6,6 (Table 12.5 ). Draw the structural formulas for two adjacent chains of nylon 6,6 and show where hydrogenbonding interactions could occur between them.
See all solutions

Recommended explanations on Chemistry Textbooks

Physical Chemistry

Read Explanation

Chemical Reactions

Read Explanation

Inorganic Chemistry

Read Explanation

Chemistry Branches

Read Explanation

Nuclear 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.