Hourly
Exam # 1 Dunnivant
Name
(PRINTED)
____________________________________
There
are 100 points. The exam will be
graded on a percentage basis.
The honor statement must be
signed in order for your exam to be graded.
Closed
book, closed Internet, closed notes, closed cell
phone, closed neighbor!
I
have neither given nor received aid on this exam.
Signature
________________________
AvogadroÕs
number = 6.022 x 1023 items/mol
amu = 1.6605 x 10-24
g
electron charge = 1.602 x 10-19 C
mass of neutron = 1.6749 x 10-24 g
mass of electron = 9.1094 x 10-28 g
mass of proton = 1.6726 x 10-24 g
F =
9/5 C + 32
K =
273.14 + C
M1 * V1 =
M2 * V2
Moles
= grams / gram atomic or molecular weight
Molar
(M) = moles/L
MW = molecular weight
AW
= atomic weight
gmw = grams molecular weight
gaw = gram atomic weight
Average
atomic weight = (fraction of abundance1 * isotope weighta) + (fraction of abundance2 *
isotope weight2) + (fraction of abundance3 * isotope
weight3) + É
NOTES: NEATNESS COUNTS AND POORLY DISPLAYED OR
PRESENTED WORK WILL BE DISCOUNTED!!!!!!!!!!!!!
-Show all work for partial
credit.
-CIRCLE FINAL ANSWERS in
math problems
-Significant figures and
units will be graded throughout the exam.
1. (2 pts) Analogy: A molecule is to a compound as
a) an electron is to a proton
b) a proton is to a nucleus
c) an isotope is to an element
d) an atom is to an element
2. (1 pt each) In chemistry we have three distinct phases:
solid, liquid, and gaseous. Give
an example of something that lies at the interface of each phase boundary. (i.e. what substance/thing contains both a gas and a liquid?,
and so on)
Air/liquid interface:
Air/solid interface:
Liquid/solid interface:
3. (1 pt each) List five
physical properties of water.
_______________________________
_______________________________
_______________________________
_______________________________
_______________________________
4. (5 pts) You are on an
airplane traveling to Europe and the flight attendant announces that the temperature
is 30. C. Do you need to put on
your wool sweater upon exiting the plane?
For credit what it the temperature in F?
5. (2.5 pts each) Dalton
proposed the four statements below on atomic theory. After each statement answer the question(s).
á
Each element is composed of extremely small
particle called atoms (and atoms are indivisible and
indestructible)
Who disproved this and
what do we know today?
á
All atoms of a given element are identical
What instrument was used
to disprove this and why is this wrong?
á
Atoms of an element are not changed into
different types
of atoms by reactions; atoms are
neither created nor destroyed in
reactions
What is the exception to
this?
á
Compounds are formed when atoms of more than
one element combine; a given compound always has the same relative number and
kind of atoms.
What three Laws did this lead to?
1.
2.
3.
6. (1 pt each) Name two facts
Thomson discovered.
1.
2.
7. (1 pt each) Name three
important scientific things Rutherford did.
1.
2.
3.
8. (10 pts) Starting with the
number of electrons, protons, and neutrons that are in 40Ca and the
information on the cover sheet, estimate the gram molecular weight of this
isotope. Do your calculations not
exactly match the expected value for 40Ca? Also, why do they not match the value given in your Periodic
Table?
9. (10 pts) Lead (Pb) has four
stable isotopes. Calculate the
average gram atomic weight for Pb given the following information:
204Pb abundance is 1.40 %
206Pb abundance is 24.10 %
207Pb abundance is 22.10 %
208Pb abundance is 52.40 %
10. (5 pt each) Give a chemical
formula for (1) an ionic bonded inorganic compound, (2) a polar covalently
bonded inorganic compound, and (3) a purely covalently bonded inorganic
compound.
1.
2.
3.
11. (5 pts) 0.0255 g of NaOH are placed in a beaker and titrated with 0.0250 M HCl. How many mL of the HCl solution are needed
to reach the equivalence point?
12. (5 pts) Solubility Rules: Circle the compounds that should be present in an aqueous
solution as a solid; also place the IUPAC name beside each compound.
PbCrO4 _________________
CaCl2 _________________
(NH4)2CO3 _________________
HgCl2 _________________
Fe2O3 _________________
13. Nomenclature:
(2 pts each) Give the name or chemical formula
(which ever is missing) and the oxidation state (number) of EACH element in the
formula.
Ammonium hydroxide Formula: __________________
Oxidation
states:
Fe2(CO3)3-2H2O Name: ________________________________
Oxidation
states:
Copper(II) arsenite Formula: __________________
Oxidation
states:
(1 pt each) Write and balance chemical equations for
the following statements and predict the products: (donÕt forget to place the
subscript indicating the phase or state of each chemical)
1. Iron(II) chloride reacting with calcium hydroxide
2. Hydroiodic acid reacting with potassium hydroxide
3.
Potassium chromate reacting with cadmium nitrite
14. (10 pts) Estrone,
that contains only C, H, and O, is a female sexual hormone that occurs in the
urine of pregnant women.
Combustion analysis of a 1.893 g sample of estrone
produced 5.545 g CO2 and 1.388 g H2O. The molar mass of estrone
is 270.36 g/mol. Find the
molecular formula of estrone.
15. (10 pts) The following problem is a limiting
reagent problem that must be solved using a complete flow chart. Octane (100.0 g) is combusted in the
present of pure O2 (50.00 g).
How much CO2 and H2O will be produced?
The limiting reagent is _________________
Fill out a complete flow chart:
NOTE: If you cannot remember the chemical formula
for octane it can be purchased from me for 3 points.
Bonus Question: What does the acronym IUPAC stand for?