Study Guide answers - CHEM1013 exam 5

Arkansas State University
Department of Chemistry
and Physics

Study Guide - Answers - Exam 5

Molecular Geometry / Bonding

SO₃ SO₃^2-

a) Lewis Dot Structure

b) electron arrangement trigonal planar tetrahedral

c) molecular geometry trigonal planar trigonal pyramidal

d) the bond angles 120^o less than 109.5^o

e) formal charges S = +2
O (single bond) = -1
O (double bond) = 0 S = +1
O = -1

f) bond polarity polar covalent polar covalent

g) dipole moment no yes

h) resonance structures larger view none

i) bond distances, strengths double bond shorter and stronger than single bonds, due to resonance, all bonds the same length and strength all single bonds, same distance and strength

j) hybrid orbitals S - sp²
O (single bond) - sp³
O (double bond) - sp² S - sp³
O - sp³

k) draw orbital overlap see below see below

l) bonding (s or p) 3s, 1p 3s

m) Enthalpy of reaction from bond energies for examples, see enthalpy worksheet

Orbital overlap for SO₃

Orbital overlap for SO₃^2-

	SO₃	SO₃^2-
a) Lewis Dot Structure
b) electron arrangement	trigonal planar	tetrahedral
c) molecular geometry	trigonal planar	trigonal pyramidal
d) the bond angles	120^o	less than 109.5^o
e) formal charges	S = +2 O (single bond) = -1 O (double bond) = 0	S = +1 O = -1
f) bond polarity	polar covalent	polar covalent
g) dipole moment	no	yes
h) resonance structures	larger view	none
i) bond distances, strengths	double bond shorter and stronger than single bonds, due to resonance, all bonds the same length and strength	all single bonds, same distance and strength
j) hybrid orbitals	S - sp² O (single bond) - sp³ O (double bond) - sp²	S - sp³ O - sp³
k) draw orbital overlap	see below	see below
l) bonding (s or p)	3s, 1p	3s
m) Enthalpy of reaction from bond energies	for examples, see enthalpy worksheet