Chemistry Reference
In-Depth Information
15.
Draw the electron-dot formulas that show all important contributors to a resonance
hybrid and show their electronic relationship using curved arrows.
16.
Predict the geometry of bonds around an atom, knowing the electron distribution in
the orbitals.
17.
Draw in three dimensions, with solid, wedged, and dashed bonds, the tetrahedral
bonding around
sp
3
-hybridized carbon atoms.
18.
Distinguish between acyclic, carbocyclic, and heterocyclic structures.
19.
Given a series of structural formulas, recognize compounds that belong to the same
class (same functional group).
20.
Begin to recognize the important functional groups: alkene, alkyne, alcohol, ether,
aldehyde, ketone, carboxylic acid, ester, amine, nitrile, amide, thiol, and thioether.
ANSWERS TO PROBLEMS
Problems Within the Chapter
1.1
The sodium atom donates its valence electron to the chlorine atom to form the ionic
compound, sodium chloride.
1.2
Elements with fewer than four valence electrons tend to give them up and form
positive ions: Al
3+
, Li
+
. Elements with more than four valence electrons tend to gain
electrons to complete the valence shell, becoming negative ions: S
2-
, O
2-
.
1.3
Within any horizontal row in the periodic table, the most electropositive element
appears farthest to the left. Na is more electropositive than Al, and C is more
electropositive than N. In a given column in the periodic table, the lower the element,
the more electropositive it is. Si is more electropositive than C.
1.4
In a given column of the periodic table, the higher the element, the more
electronegative it is. F is more electronegative than Cl, and N is more
electronegative than P. Within any horizontal row in the periodic table, the most
electronegative element appears farthest to the right. F is more electronegative than
O.
1.5
As will be explained in Sec. 1.3, carbon is in Group IV and has a half-filled (or half-
empty) valence shell. It is neither strongly electropositive nor strongly
electronegative.
1.6
The unpaired electrons in the fluorine atoms are shared in the fluorine molecule.
F
+
F
F
F
+ heat
fluorine atoms
fluorine molecule
1.7
dichloromethane (methylene chloride)
trichloromethane (chloroform)
H
Cl
H
Cl
H
C
Cl
Cl
or
H
C
Cl
H
C
Cl
Cl
or
H
C
Cl
Cl
Cl
