Answers to Topic 6 Study Questions p.113-
Part A
1.
4
8.
2
9.
3
2.
2
3.
3
4.
1
5.
3
6.
3
7.
3
10.
11.
12.
2
1
3
13.
1
14.
2
15.
3
Part B
16.
4
17.
3
18.
1
19.
3
20.
2
21.
1
22.
23.
24.
4
25.
2
26.
27.
28.
29.
2
1
1
1
3
2
30.
Part C
31.
The electronegativity difference between Hydrogen and Fluorine is larger (4.0-2.1 = 1.9
) than the difference between Hydrogen and Iodine (2.7 – 2.1 = 0.6
), making the H-F bond more uneven, more polar.
32.
Sulfur
33.
The distribution of charge is even, or symmetrical, making the molecule nonpolar.
34.
The electronegativity differen ce between Carbon and Oxygen is 3.5 – 2.6 = 0.9
, making it a polar bond. There is no difference between two fluorine molecules, (4.0 – 4.0 = 0 ), making the
F-F bond entirely nonpolar.
35.
Fluorine molecule and Iodide ion
36.
The extrapolated boiling point for water (just estimate by extending the line) would be around -
75 o
C. This would be expected between water is so light. The real boiling point, however, is
100 o
C, because water is so polar. This means water has strong intermolecular forces (even hydrogen bonding) which hold the molecules in the liquid phase and make it more difficult to boil.
37.

38.
39.
This is a silly question, don’t answer it. Just memorize you electronegativity differences
(0 - 0.3 = nonpolar covalent, 0.3 – 1.7 = polar covalent, 1.7 – 4.0 = ionic).
40.
An ionic bond would form between a metal and chlorine (a nonmetal).
41.
Metal M must be a member of group 2 on the periodic table. Hint: Look at the formula MCl
2 and “uncross” the subscripts to reveal that the metal should be a +2 ion to bond with chlorine in that ratio.
42.
After reacting the chlorine in the compound is now a chloride ion (Cl
-1
), so he has the same electrons as Argon. We do not have enough information to know which noble gas the mystery metal is isoelectronic with.
43.
An aqueous solution of the compound conducts an electric current because it is ionic and breaks into positive and negative ions when it dissolves. These ions can carry electrical charge because they have charges themselves.
44.
The oxidation number of the metal would be +2 (see explanation in the answer to 41).
45.
A P-Cl bond would be more polar than a P-S bond because the electronegativity difference between Phosphorus and Chlorine (3.2 – 2.2 = 1.0
) is greater than the difference between
Phosphorus and Sulfur (2.6 – 2.2 = 0.4
).
46.
A polar covalent bond would be formed between Phosphorus and Chlorine (electronegativity difference is 1.0, which is between 0.3 and 1.7).
47.
The oxidation number of Metal X would be +1 if it reacts with Iodine in a 1:1 ratio (because iodine wants to be the -1 iodide ion).
48.
An ionic bond would form metal X and iodine (a nonmetal).
49.
Because X is a metal it is a good conductor of electricity because it has mobile electrons throughout the material.
50.
If the ion is smaller than the original atom, the element must be a metal. Metals react (with nonmetals) by losing electrons, becoming smaller, and getting a positive charge .