TEAR OFF FRONT PAGE (FORMULA SHEET)
NA = 6.022 x 1023
1 amu = 1.661 x 10-27 kg
h = 6.626 x 10-34 Js
c = 2.998 x 108 m/s
deBroglie = h/mv
C = (5/9) (F – 32)
C = K - 273.15
c = 
Ephoton = h = hc/
(x)(mv)  (h/4)
F ~ Q1 Q2
 = Qr
d2
1 Debye = 3.336 x 10-30 Cm
1 Å = 10-10 m
-19
Electron charge = 1.6022 x 10 C
F = (9/5)(C) + 32
K = C + 273.15
EK = 1/2mv2
(1/) = RH [ (1/nf2) - (1/ni2) ]
RH = 1.097 x 10-2 nm
EH = - (2.18 x 10-18 J)/n2
% ionic character = (observed) x 100%
(calculated)
GENERAL CHEMISTRY 1
SECOND HOUR EXAM
SAMPLE
Name
________________________________________________
Panthersoft ID ________________________________________________
Signature
________________________________________________
Part 1 ________________ (20 points)
Part 2 ________________ (48 points)
Part 3 ________________ (32 points)
TOTAL ________________ (100 points)
Do all of the following problems. Show your work.
2
Part 1. Multiple choice. Circle the letter corresponding to the correct answer. There is one and only one correct
answer per problem. [4 points each]
1) Which of the following elements is a metalloid?
a) Ar
b) As
B
c) Be
d) Cr
e) Pb
2) Which of the following substances is a molecular compound?
a) CO2
b) HNO2
E
c) SO2
d) Both a and b
e) Both a and b and c
3) What is the correct chemical formula for the ionic compound that forms from the elements calcium (Ca) and
nitrogen (N)?
a) Ca3N2
b) Ca2N2
A
c) Ca2N3
d) CaN
e) cannot tell from the information given
4) The correct name for the ClO3- ion is
a) perchlorate ion
b) hypochlorite ion
D
c) chlorite ion
d) chlorate ion
e) chlorine trioxide ion
5) Which of the following statements about covalent bonds between nitrogen atoms is correct?
a) The bond length for a nitrogen single bond is shorter than for a nitrogen double bond
b) The bond energy for a nitrogen single bond is smaller than for a nitrogen double bond
B
c) The bond energy for a nitrogen single bond is larger than for a nitrogen double bond
d) Both a and b
e) Both a and c
3
Part 2. Short answer.
1) Give the number of protons, the number of neutrons, the number of electrons, and the approximate mass (in amu)
for the following particle. [4 points]
71
Ga3+
number of protons
____31______
number of electrons
____28______
number of neutrons
____40______
approximate mass (amu)
____71______
2) Give the electron configuration for the Ti2+ ion. [4 points]
Ti = 1s 2s2 2p6 3s2 3p6 4s2 3d2 ; soTi2+ = 1s2 2s2 2p6 3s2 3p6 3d2
3) For each of the following questions circle the correct answer. There is one and only one correct answer per
question. [3 points each]
a) Which of the following is the largest atom?
Li
Na
O
S
b) Which of the following has the largest first ionization energy?
Li
Na
O
S
O
S
O2-
S2-
c) Which of the following is the most metallic element?
Li
Na
d) Which of the following is the largest ion?
Li+
Na+
e) Which of the following is the most electronegative element?
Ba
Ca
Po
4
Se
4) Provide the missing information. [3 points each]
Formula
Name
CuCl2
copper II chloride
HNO2
nitrous acid
NF3
nitrogen trifluoride
5) What is the percent by mass of oxygen in Fe(NO3)2? [6 points]
Fe
1 x 55.85 amu
=
55.85 amu
N
2 x 14.01 amu
=
28.02 amu
O
6 x 16.00 amu
=
96.00 amu
M = 179.87 amu
% oxygen by mass = 96.00 amu x 100% = 53.37 %
179.87 amu
6) Give Lewis structures for the following molecules or ions. [5 points each]
a) HCFO
b) CH3CH2OCH3
5
Part 3. Problems.
1) Stearic acid (C18H36O2) is a fatty acid found in beef and butter.
a) What is M, the molecular mass, of stearic acid? Give your answer in units of g/mol. [6 points]
C
H
O
18 (12.01)
36 (1.01)
2 (16.00)
284.54 g/mol
b) How many oxygen atoms are present in 1.000 g of stearic acid? [10 points]
Let SA = stearic acid, then
# atoms O = 1.00 g SA
1 mol SA
284.54 g SA
6.022 x 1023 atom O = 4.23 x 1021 O atoms
1 mol O
2 mol O
1 mol SA
2) Gahnite is a naturally occurring mineral containing aluminum (Al), oxygen (O), and zinc (Zn). A sample of the
pure mineral was analyzed, and the following results obtained (percentages are by mass):
% Al = 29.54 %
% O = 34.75 %
% Zn = 35.71 %
Based on this information find the empirical formula for gahnite. Show your work. [16 points]
Assume 100.0 g of gahnite. Then
mol Al = 29.54 g Al
1 mol Al = 1.095 mol / 0.5459 mol = 2.006
26.98 g Al
mol O = 34.75 g O
1 mol O
16.00 g O
mol Zn = 35.71 g Zn
1 mol Zn = 0.5459 mol / 0.5459 mol = 1.000
65.41 g Zn
= 2.172 mol / 0.5459 mol = 3.979
So the empirical formula is Al2O4Zn
6