Download 1 1. (8 pts) Circle the formula (only one) that best fits each of the

1.
(8 pts) Circle the formula (only one) that best fits each of the following descriptions:
a.
largest radius
O
O–
O2–
b.
stronger acid (first ionization)
HNO3
H3PO4
H2SO4
c.
largest radius
N3–
O2–
F–
e.
highest boiling point
NH3
H2O
N2H4
2.
(8 pts) By considering the bonding in liquids and solids, arrange the following substances from highest to lowest
melting point.
NaCl
Na
Cl2
SiO2
3.
(6 pts) Draw the Lewis structures. Circle the shortest nitrogen-oxygen bond. In each of the molecules, nitrogen is the
central atom.
H2NOH
4.
N2O
NO2–
NO3–
(6 pts) Circle the longest nitrogen-oxygen bond. In each of the molecules, nitrogen is the central atom.
H2NOH
N2O
NO2–
NO3–
5. (6 pts) Write balanced reactions for each of the following.
a. complete combustion of 2-methyl-2-propanol
b. the oxidation of aluminum metal in air
1
6. (4 pts) Give the systematic name for the following compounds.
[Co(en)2Br2]Cl
7.
(4 pts) The complex [Co(en)2Br2]Br is low spin. Draw the d-orbital diagram, including the electrons.
E
8.
(4 pts) The color of an aqueous solution of [Ni(H2O)6]2+ is green and the color of an aqueous solution of
[Co(H2O)6]2+ is red. Which solution absorbs light of longer wavelength?
a) [Ni(H2O)6]2+
9.
b) [Co(H2O)6]2+
(4 pts) Draw the optical isomers of alanine.
10. (4 pts) Draw the structural formulas for each of the following.
a. cis-2,3-dichloro-2-hexene
b. 1,3,5-trinitrobenzene
11. (4 pts) Draw an aldehyde that is an isomer of acetone (dimethyl ketone).
2
12.
a)
(2 pts) Aspartame, the artificial sweetener marketed under the name NutraSweet, is a methyl ester of a dipeptide.
Circle the asymmetric carbon atoms (chiral centers) in the structure of aspartame shown.
O
COOCH3
H2N – CH – C – NH – CH – CH2
CH2COOH
b) (6 pts) What two amino acids are used to prepare aspartame. Draw the structures of the two amino acids.
13. (22 pts) Circle the formula (only one) that best fits each of the following descriptions:
a. binds more strongly to hemoglobin CO
O2
b. higher boiling point
CH3CH2OH
CH3OCH3
c. highest melting point
CCl4
HCl
NaCl
d. lowest vapor pressure at 25oC
SiO2
CO2
H2O
e. is the smallest ion
F–
Na+
Mg2+
f. lowest freezing point
CH4
H2
CO
g. highest ∆H vaporization
HF
HCl
h. greatest polarizability
He
Ne
i. stronger bond
Si–Si
Si–O
j. most ionic in character
H2S
SO2
P2S3
K2S
k. strongest bond
Na–Na
K–K
Li–Li
Rb–Rb
Ar
Al3+
Kr
14. (6 pts) H3PO2 is a monoprotic acid. Draw the structure and circle the acidic hydrogen.
3
15.
(8 pts) What is the hybridization on the four carbon atoms indicated?
O
O H C – O – CH3
NH2CH2C – N – C = CH2
1
16.
2
3
4
Hybridization on first carbon:
Hybridization on third carbon:
Hybridization on second carbon:
Hybridization on fourth carbon:
(4 pts) Indicate the bond angles, a, b, c and d.
O
d
O H C – O – CH3
a
NH2CH2C – N – C = CH2
b
17.
18.
c
Angle a:
Angle c:
Angle b:
Angle d:
(8 pts) Indicate the dominant intermolecular force for each of the following substances.
a) SeF2
b) CH2O
d) CH3CH3
e) (NH2)2CO
(4 pts) A substance does not conduct electricity unless it is melted. It is hard and has a high melting point. These
properties are characteristic of which one of the following crystalline solids? Circle the correct answer.
a) ionic
b) metallic
c) molecular
d) covalent (atomic network)
19. (6 pts) Indicate the type of crystalline solid formed for each of the following substances.
a) Diamond
b) P4
c) Ca
4
20. (4 pts) The structures for cyclobenzophenone and cyclohexanone are shown as follows.
O
O
cyclobenzophenone
21.
cyclohexanone
a) Are all the atoms in the same plane in the cyclobenzophenone? Circle the answer.
Yes
No
b) Are all the atoms in the same plane in the cyclohexanone? Circle the answer.
Yes
No
(4 pts) Write the electron configuration and the bond order predicted by the MO model for each of the following species.
electron configuration
bond order
a. CN
b. CN–
22.
(4 pts) Draw the structure of Leu-Ala-Cys in that order.
23.
(4 pts) Circle the chiral carbons in the following molecule, progesterone.
O
CH3
C
CH3
CH3
O
24.
(4 pts) Polyvinyl chloride is an addition polymer of chloroethene (commonly called vinyl chloride). Draw the
repeating unit for polyvinyl chloride.
CH2=CHCl
5
25.
(8 pts) A solution is made by dissolving 25.0 g of urea, (NH2)2CO, in 275 g of water. Calculate the vapor pressure of
this solution at 25oC. The vapor pressure of pure water is 23.8 torr at 25oC.
26.
(10 pts) You have a 10.40 gram mixture of table sugar (C12H22O11) and table salt (NaCl). When this mixture is
dissolved in 150 grams of water, the freezing point is –2.24oC. Calculate the percent by mass of sugar in the dry
mixture. Kf = 1.86 oC kg / mol
27.
Write the balanced equation for the condensation reaction of each of the following.
a.
(3 pts) Condensation of acetic acid (CH3COOH) with ethyl alcohol to produce an ester.
b.
(3 pts) Condensation of glycine with dimethyl amine to produce an amide.
6