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?

Name: Chemistry: The Central Science
Author: Brown
ISBN: 9780134414232

Verified step by step guidance

Identify the hybridization of each carbon atom in the polyethylene structure. Each carbon atom forms four sigma bonds (single bonds), which indicates sp3 hybridization.

Recall that sp3 hybridization involves the mixing of one s orbital and three p orbitals to form four equivalent sp3 hybrid orbitals.

Determine the bond angles for sp3 hybridized carbon atoms. The ideal bond angle for sp3 hybridization is 109.5 degrees.

Observe the 3D structure of the polyethylene chain. The solid wedges indicate bonds coming out of the plane, and the dashed wedges indicate bonds going behind the plane.

Conclude that each carbon atom in the polyethylene chain is sp3 hybridized, and the bond angles between the carbon atoms are approximately 109.5 degrees.

Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Hybridization

Hybridization is the concept of mixing atomic orbitals to form new hybrid orbitals that can accommodate the bonding requirements of atoms in a molecule. In the case of polyethylene, the carbon atoms undergo sp3 hybridization, where one s orbital and three p orbitals combine to form four equivalent sp3 hybrid orbitals, allowing for tetrahedral geometry around each carbon atom.

Bond Angles

Bond angles are the angles formed between adjacent bonds in a molecule. For sp3 hybridized carbon atoms, the ideal bond angle is approximately 109.5 degrees, which arises from the tetrahedral arrangement of the hybrid orbitals. This angle minimizes electron pair repulsion, leading to a more stable molecular structure.

Molecular Geometry

Molecular geometry refers to the three-dimensional arrangement of atoms within a molecule. In linear polyethylene, the carbon backbone is arranged in a straight chain, which influences the physical properties of the polymer. The presence of hydroxyl groups (–OH) also affects the geometry and interactions, contributing to the overall stability and characteristics of the polymer.

Recommended video:

Guided course

01:33

Molecular Geometry with Two Electron Groups

Related Practice

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

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).

350

views

Textbook Question

(a) In polyvinyl chloride shown in Table 12.6, which bonds have the lowest average bond enthalpy?

2242

views

Textbook Question

One method to synthesize ionic solids is by the heating of two reactants at high temperatures. Consider the reaction of FeO with TiO₂ to form FeTiO₃. Determine the amount of each of the two reactants to prepare 2.500 g FeTiO₃, assuming the reaction goes to completion. (a) Write a balanced chemical reaction. (c) Determine the moles of FeTiO₃.