Download Chemistry 2202 Chemical Bonding Review Answer the following in

Chemistry 2202
Chemical Bonding Review
Answer the following in the space provided.
1.
Classify the following substances given their physical properties.
Substance
(classify here)
Physical Properties
SATP State
Boiling/Melting
Pt.
Electrical
Conductivity
Solubility in
Water
hard brittle
solid
extremely high
not in any state
no
malleable solid
high
only as solid or liquid
no
colorless gas
low
not in any state
yes
brittle solid
high
only as liquid or
aqueous
yes
2.
Sodium chloride and sugar have different bond types, yet these both dissolve in water. Explain.
3.
Draw electron dot diagrams for the first 20 elements on the periodic table. What is the main difference
between metals and non metals?
4.
Give are the number of bonding electrons and lone pairs for each of the following atoms. ( H, C, Mg,
He, O, P, N, Ca, Si )
5.
For each of the following, i) draw the appropriate Lewis electron dot diagram, ii) draw the structural
diagram following the VSEPR theory, iii) indicate the polarity (polar or non- polar) and iv) describe the
shape around each central atom.
a.
C2H5OH
b.
PH3
c.
H2S
d.
CO2
e.
C2H3Br
6.
What is the difference between bond dipoles and molecular dipoles? Illustrate this difference using
examples.
7.
Two of the hardest substances known are diamond, Cn , and silicon carbide, SiC. Account for their
extra-ordinary hardness in terms of the chemical bonds involved.
8.
Why does chlorine have a higher boiling point than fluorine?
Alkanes
Boiling Pt.
Alcohols
Boiling Pt.
methane, CH4(g)
-161C
methanol, CH3OH(l)
64.5C
ethane, C2H6(g)
-88.6C
ethanol, C2H5OH(l)
78.5C
propane, C3H8(g)
-44.5C
propanol, C3H7OH(l)
97.4C
butane, C4H10(g)
-0.5C
butanol, C4H9OH(l)
117.3C
pentane, C5H12(l)
36C
hexane, C6H14(l)
69C
Answer the following 3 questions by referring to the table above
9.
CH3Cl(g) has a boiling point of -23.7C.
a.
Account for the difference in boiling point between CH3Cl(g) and propane.
b.
Account for the difference in boiling point between CH3Cl(g) and ethanol.
10.
Hexanol, C6H13OH(l), has a boiling point of 156C. What prediction can we make about the boiling
point of pentanol, C5H11OH(l)? Explain.
11.
Ethene has the formula C2H4(g). What prediction can we make about its boiling point? Explain.
12.
Which is more polar, hydrogen chloride or hydrogen fluoride? Why?
13.
Can you tell which of the following compounds, C5H12 or CH3OH, has the larger boiling point? Why or
why not?
14.
Rank the following in order of increasing boiling point (lowest to highest) and explain why they are
ranked that way.
a.
CH3Cl
b.
C3H8
c.
C2H5OH
d.
SiC
15.
Use bonding theory to explain the following phenomena.
a.
Ice floats in liquid water.
b.
A stream of water will bend when a charged object is brought close to it.
c.
A small needle can sit on the surface of water in a bowl without getting wet.
d.
Cooking oil will not mix with water.
16.
Using electron dot diagrams, explain the formation of monatomic ions found in magnesium oxide.
17.
Explain the difference in the information given by the formulas NaCl and NH3.
18.
Explain why ionic compounds are brittle while metallic compounds are malleable and ductile.
19.
Why does a metal conduct electricity in any phase while ionic compounds only conduct electricity in the
liquid or aqueous phase but not as a solid?
20.
Explain the following statement: “Although we classify compounds as ionic or molecular using the
staircase line on the periodic table, there is no definite dividing line between ionic compounds and
molecular compounds.”
Chemical Bonding Terminology
valence electrons
electronegativity
ionic bond
covalent bond
bonding electrons
lone pairs
bonding capacity
single covalent bond
double covalent bond
triple covalent bond
polar covalent bond
nonpolar covalent
bond
bond dipole
molecular dipole
dispersion forces
dipole-dipole forces
hydrogen bonding
network covalent
bond
ionic crystal lattice
formula unit
empirical formula
metallic bond
malleable
ductile