REVIEW FOR BONDING –STATES EXAM – FROM REVIEW
BOOK CH 4
4:17 to 4:19
1)Bondig occurs to increase stability  energy kinetic is
released (exothermic) this energy was stored (potential).
answer is #1potential E
2) N(g) + N(g)  N2(g) + energy
The two N atoms are joined with the nonpolar covalent Bond
formed, and energy is a product and is released –exothermic
ANS is #4
3) The attraction for electrons is electro negativity, the lowest
is Na because: 1- it is towards the top-left of the table
AND/OR table S assigns it the lowest electro negativity
of all the choices.
ANSWER is Na
4:17 # 4– To solve calculate the ionic character for each
combination of elements. Aluminum has an electronegativity of
1.6 and gives the greatest ionic character with oxygen. And is
Al. NOTE – this is a badly worded question – the least
electronegative element element will allow O to share the most
of its cloud, that is Al, the most electronegative element will
have the greatest pull on the O electrons, that is S.
#7 Ionic substances have ionic character of 1.7 or above.
MgCl2 is the answer (3.2-1.3) = 1.9 ionic character. Also you
have an active metal with a halogen.
#9 All of them have H, therefore it is the other element that
determines the ionic character. The greatest difference is with F
(4.0 –2.1) = 1.9 ionic character.ANS is choice 2
#12 – Sr is in group two, therefore it will become a 2+ ion by
losing 2 electrons, the ground state ATOM will have 2 more
electrons than the ION. Choice 1 is ans.
#13- They tell you that it conducts in the (l) and dissolved (aq)
situations. This implies that it does not conduct in the solid
state. They also mention crystalline solid. This is an ionic
substance – choice 1
#14- NaCl(l) is ionic based on ionic character and it is a
liquid,This is your answer as it will be conductive. NaCl(s)
cannot conduct. C6H12O6 is covalent and does not conduct.
#18 F2 is nonpolar as the ionic character is 0, also two of the
same atoms will share electrons equally. ANS is 2.
25. Covalent substances form molecules, no other type of
substance does. Look for an ionic character of between 0 and
1.7 ans. is CO2
27. Soft and nonconductive indicates covalent compounds. The
terms covalent and molecular are interchangeable in this
context. AND is 1
29. The only solid conductors are metallic and
graphite. Metals are known to conduct in all
phases. AND is 1
#36
Al + 3 F  Al3+ + 3F-
F
[
F
[
F
F
[
+
[ F
-
[

Al
Al+3
[
F
-
-
38)
a) Hard, high M.P and High B.P solid conductor is a metal.
b) Hard, high M.P and High B.P liquid conductor is ionic
c) Soft, low m.p. nonconductor is covalent (molecular).
4:27 # 1
H
H
c
H
H
1. The molecule is symmetrical and
therefore cannot be polar.
2. The geometry is 4 bonds – tetrahedral
–and symmetrical geometry.
3. Carbon is the most electronegative
atom and is therefore the d-, and the H
atoms are the = pole.
#3 Hydrogen bonds are strongest when polar charges are
most concentrated (density) which means small radius and
high electronegativity. Choice 3.
#4 Hydrogen bonding is a type of dipole attraction between H
and F, O or N. As a dipole attraction, the relative strength of
attraction between different atoms increases with the relative
ionic character between them. The ionic characters are:
H2O ionic character is 1.4 very polar
H2S ionic character is 0.5 weakly polar
H2Se ionic character is 0.5 weakly polar
H2Te ionic character is 0.0 totally nonpolar!
6-Dispersion forces (Van der Waals) increase in strength
directly with molar mass (atomic mass for atoms). In this
question He is the smallest ans. has the weakest forces.
8- In this question all of the atoms are noble gasses. The
answer is 4 because they go from the largest (Xe) to the
smallest choice (Ne). Dispersion forces become weaker with
decreasing mass.
14 – molecule-ion attractions are found when IONIC
substances dissolve in water. In these choices the answer is
KCl (aq). Hint look for the (aq) aqueous symbol.
MOLECULE TO ION
ATTRACTION ATTRACTION
THE
MOLLECULE
TO ION
ATTRACTION
BETWEEN
THE δ+ OF
THE
HYDROGEN
POLE OF
WATER AND
THE – ION.
- ION
δ+
δ+
H
H
OXYGEN
δ-
MOLLECULE
ION
ATTRACTION
S ARE VERY
STRONG
AND HARD
TO BREAK,
MAKING THE
SEPARATION
OF WATER
AND SALTS
CONSUME
LARGE
AMMOUNTS
OF ENERGY.
δ+
δ+
H
H
OXYGEN
δ-
+ ION
THE
MOLLECULE
TO ION
ATTRACTION
BETWEEN
THE δ- OF
THE OXYGEN
POLE OF
WATER AND
THE + ION.
15- As in the diagram - the positive hydrogen pole of water
faces a – ion, the negative oxygen pole attracts to the + ions.
ANS is 4.
18- The empirical formula is the one with the most reduced
subscripts, Answer is K2O cause 2 and 1 cannot be reduced.
24 Calcium Phosphate is
Ca 2+
GROUP 2
IS 2+
PO43PHOSPHATE
IS 3+,TABLE E
Ca3(PO4)2