Textbook Question
(a) What are the C—C—C bond angles in diamond?
583
views
Ch.12 - Solids and Modern Materials
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232
Not the one you use?Change textbookSelect a different textbook
Table of contents
- Ch.1 - Introduction: Matter, Energy, and Measurement140
- Ch.2 - Atoms, Molecules, and Ions192
- Ch.3 - Chemical Reactions and Reaction Stoichiometry172
- Ch.4 - Reactions in Aqueous Solution156
- Ch.5 - Thermochemistry151
- Ch.6 - Electronic Structure of Atoms137
- Ch.7 - Periodic Properties of the Elements127
- Ch.8 - Basic Concepts of Chemical Bonding143
- Ch.9 - Molecular Geometry and Bonding Theories167
- Ch.10 - Gases147
- Ch.11 - Liquids and Intermolecular Forces97
- Ch.12 - Solids and Modern Materials129
- Ch.13 - Properties of Solutions126
- Ch.14 - Chemical Kinetics175
- Ch.15 - Chemical Equilibrium107
- Ch.16 - Acid-Base Equilibria127
- Ch.17 - Additional Aspects of Aqueous Equilibria133
- Ch.18 - Chemistry of the Environment88
- Ch.19 - Chemical Thermodynamics140
- Ch.20 - Electrochemistry137
- Ch.21 - Nuclear Chemistry99
- Ch.22 - Chemistry of the Nonmetals66
- Ch.23 - Transition Metals and Coordination Chemistry69
- Ch.24 - The Chemistry of Life: Organic and Biological Chemistry11
Brown14th EditionChemistry: The Central ScienceISBN: 9780134414232Not the one you use?Change textbook
Chapter 12, Problem 127
Employing the bond enthalpy values listed in Table 8.4, estimate the molar enthalpy change occurring upon (a) polymerization of ethylene. (b) formation of nylon 6,6. (c) formation of polyethylene terephthalate (PET).
Verified step by step guidance1
Identify the chemical reaction involved in the formation of polyethylene terephthalate (PET). PET is typically formed through a condensation reaction between terephthalic acid and ethylene glycol.
Write the balanced chemical equation for the formation of PET. This will help in identifying the bonds broken and formed during the reaction.
List the bond enthalpy values for all the bonds involved in the reactants and products. You will need the bond enthalpies for C-H, C-C, C=O, O-H, and C-O bonds.
Calculate the total energy required to break all the bonds in the reactants. This involves multiplying the bond enthalpy of each bond by the number of such bonds in the reactants and summing them up.
Calculate the total energy released in forming all the bonds in the products. Again, multiply the bond enthalpy of each bond by the number of such bonds in the products and sum them up.
Key Concepts
Here are the essential concepts you must grasp in order to answer the question correctly.
Bond Enthalpy
Bond enthalpy, or bond dissociation energy, is the amount of energy required to break one mole of a specific type of bond in a gaseous molecule. It is a crucial concept in thermochemistry as it helps predict the energy changes during chemical reactions. Higher bond enthalpy values indicate stronger bonds, which require more energy to break, influencing the overall enthalpy change of a reaction.
Molar Enthalpy Change
Molar enthalpy change refers to the change in enthalpy per mole of a substance during a chemical reaction. It is calculated by considering the bond enthalpies of the reactants and products involved. This concept is essential for estimating the energy absorbed or released during the formation or breaking of chemical bonds, allowing for the prediction of reaction feasibility and stability.
Polyethylene Terephthalate (PET) Formation
Polyethylene terephthalate (PET) is a polymer formed through the condensation reaction of terephthalic acid and ethylene glycol. Understanding the formation of PET involves recognizing the types of bonds formed and broken during the reaction. The enthalpy change associated with this process can be estimated using bond enthalpy values, which helps in assessing the energy efficiency and stability of the polymerization reaction.
Related Practice
Textbook Question
Although polyethylene can twist and turn in random ways, the most stable form is a linear one with the carbon backbone oriented as shown in the following figure:
The solid wedges in the figure indicate bonds from carbon that come out of the plane of the page; the dashed wedges indicate bonds that lie behind the plane of the page. (a) What is the hybridization of orbitals at each carbon atom? What angles do you expect between the bonds?
352
views
Textbook Question
(c) What atomic orbitals are involved in the stacking of graphite sheets with each other?
543
views
Textbook Question
Silicon has the diamond structure with a unit cell edge length of 5.43 Å and eight atoms per unit cell. (a) How many silicon atoms are there in 1 cm3 of material?
Textbook Question
(b) What are they in graphite (in one sheet)?
Textbook Question
(a) In polyvinyl chloride shown in Table 12.6, which bonds have the lowest average bond enthalpy?
2242
views