Semester Exam Review
These are all the review questions from
our 5 exams.
Before using a bunsen burner, be
safe by making sure your…
• Hair is tied back; ID badge is not dangling, etc.
What piece of measurement
equipment have we used that does
not require you to estimate a digit?
• electronic balance
What must be on file for all
chemicals in the stockroom?
• MSDS – material safety data sheet
What is this piece
of equipment
called?
• Erlenmeyer flask
Which of these numbers has the
most significant figures?
8.020 E -5
60,400
.0000204
5.4 x 106
• 8.020 E -5 (4 SF)
Perform the following calculation and
express your answer to the proper number
of significant figures:
338.715 mL - 241.6 mL
• 97.1 mL
(round to tenths place)
Perform the following calculation and
express your answer to the proper number
of significant figures:
14.8 g / 27.01mL
• 0.548 g/mL
(3 S.F.)
Perform the following calculation and
express your answer to the proper number
of significant figures:
11.2 cm x 1.20 cm x 1.178 cm
• 15.8 cm3
Convert 12.5 g into ounces
(1 ounce = 28.35 g)
• 0.441 ounces
Which of the following units would be used
to express a density?
cm2
g/m
kg/mL
L
• Kg/mL
(mass/volume)
Iron has a density of 7.87 g/mL.
What would the volume of a 3.0 g piece of
iron be?
• 0.38 mL
Change this number to scientific
notation:
7000 g
• 7E3g
or
7 x 103 g
(1 S.F.)
What volume in mL
would you record from
this graduated
cylinder?
• 103.62 mL
(5 S.F.)
Perform the following calculation and
express your answer to the proper number
of significant figures:
3.18 E -5 g
• 4.5 x 102 g/mL
/
7.0 E -8 mL
or
450 g/mL
Name 1 extensive physical property
• Mass, length, volume, etc.
Which of these properties could be used to
identify an unknown substance?
Length
density
weight
volume
• Density (an intensive property)
All pure substances must be either an
_______ or a _______
• Element or compound
A mixture of sand and salt could be
separated using their differences in ______
• solubility
A mixture of water and alcohol could be
separated using this technique
• distillation
A mixture of sand and water could be
separated using this technique
• filtration
What is the frequency of light
with a wavelength of 560. nm?
•5.36 E 14 Hz
Calculate the energy of a photon
with a frequency of 7.35 E 8 Hz
•4.87 E -25 J
Which of the following photons
has the highest frequency?
l=700 nm
l=3.5 E -7 nm
n=8.2 E 14 Hz
•l=3.5 E -7 nm
Which of the following photons
has the least energy?
l=700 nm
l=3.5 E -7 nm
n=8.2 E 14 Hz
•l=700 nm
Which of the following photons
would be visible?
l=275 nm
l=645 nm
l=3.2 E -11 m
•l=645 nm (between 400 and 700 nm)
Calculate the energy of a photon
with a wavelength of 4.72 E -6 m
•4.21 E -20 J
Which scientist is credited with
discovering the nucleus?
• Rutherford
Which scientist studied
experiments with light to describe
the orbits (or energy levels) where
electrons exist
• Bohr
Which scientist proved the
existence of subatomic particles?
•Thomson (discovery of negatively charged
patrticles)
The existence of _________
disproved Dalton’s theory that all
atoms of an element were
identical.
• isotopes
Set up your white board like this
# protons
# neutrons
# electrons
For the following atoms or ions, give the
numbers of protons, neutrons, and
electrons.
a neutral atom of manganese with
a mass number of 55
• 25, 30, 25
argon-41
• 18, 23, 18
a potassium-39 cation with a +1
charge
• 19, 20, 18
A neutral atom of beryllium with a
mass number of 9
• 4, 5, 4
A +1 potassium cation with a mass
number of 39
• 19, 20, 18
platinum-194
• 78, 116, 78
hydrogen-3
• 1, 2, 1
a -3 anion of arsenic-75
• 33, 42, 36
88Sr2+
38
• 38, 50, 36
Write the electron configuration
for the element potassium
•1s22s22p63s23p64s1
Write the electron configuration
for the element titanium
•1s22s22p63s23p64s23d2
Write the noble gas configuration
for the element rubidium
•[Kr]5s1
Write the orbital notation for the
element carbon
•↑↓ ↑↓
1s
2s
↑
↑
2p
.
What element is in group 6 of
period 4?
•Cr
What element in period 4 makes
an ion with a -2 charge?
•Se
What element has 4 valence
electrons in the 2nd energy level?
•C
What halogen is located in
period 4?
•Bromine
What charge would the ion of an
alkaline earth metal have?
•+2
A group on the periodic table
contains the most reactive metals.
How many valence electrons do
these elements have?
•1
(alkali metals)
Which of the following elements
experiences the most shielding?
aluminum
mercury
antimony
rubidium
•Hg -
5 energy levels of shielding
Which of the following elements
would have the smallest atomic
radius?
As
•As
Ag
Cr
K
___________ is the tendency of
an element to attract shared
electrons in a covalent bond.
•Electronegativity
Which of the following elements
would have the lowest ionization
energy?
Rb
•Rb
Sr
Na
Li
Which of the following elements
would have the highest
ionization energy?
K
•Kr
Ca
As
Kr
Which of the following elements
has the lowest electronegativity?
Si
•Sr
Sr
Br
O
Which of these elements would
make a covalent bond with
nitrogen?
Al
•C
Mg
Ba
C
Which of these elements would
make an ionic bond with
chlorine?
O
•Li
F
Li
Xe
Polyatomics: Charges
PO4-3
PO3-3
BO3-3
AsO4-3
SO4-2
SO3-2
CO3-2
CrO4-2
NO3-1
NH4+1
NO2-1
ClO3-1
ClO2-1
BrO3-1
OH-1
CH3COO-1
HCO3-1
CN-1
Polyatomics: How many oxygens?
BO3 CO3 NO3
PO4 SO4 ClO3
CrO4
4 oxygens
3 oxygens
These are the formulas for the
ions with –ate” endings. With
one less oxygen, they would be
“-ite” ions.
AsO4
BrO3
5 ions don’t follow this:
Cyanide CN-1
Hydroxide OH-1
Bicarbonate HCO3-1
Acetate CH3COO-1
Ammonium NH4+1
Write the formula for the only
polyatomic anion below:
ammonium
bicarbonate
sulfide
bromide
•HCO3-
What polyatomic ion is this:
NO2
•nitrite
What polyatomic ion is this:
-2
SO4
•sulfate
What polyatomic ion is this:
OH
•hydroxide
Write the formula for ammonium
chloride
•NH4Cl
Write the formula for sodium
chromate
•Na2CrO4
Write the formula for calcium
cyanide
•Ca(CN)2
What is the name of this
chemical:
SrO
•Strontium oxide
What is the name of this
chemical:
Al(BrO3)3
•Aluminum bromate
What is the name of this
chemical:
Fe(ClO3)3
•Iron (III) chlorate
Write the formula for trinitrogen
monoxide
•N3O
Write the formula for carbonic acid
•H2CO3
Write the formula for propane
•C3H8
Write the formula for cyclohexane
•C6H12
Lewis Structures and Geometries
1. Fill out NASL
– consider ion charge with A
2. Choose central atom
– never H, always C if present, otherwise
whichever element is furthest from
Fluorine)
3. Bond atoms to central atom using
shared electrons (2 electrons per
bond)
– if it seems like there are too many shared,
make double or triple bonds
– if more shared needed, borrow from lone
4. Fill in lone pairs so every atom has
its octet
– central atom can have more than an octet
* On central atom only
Geometry
Bonded
atoms*
Lone
pairs*
Linear
Bent
Trigonal Planar
2
2
3
0
2
0
Trigonal
Pyramidal
Tetrahedral
See-saw
3
1
4
4
0
1
Trigonal
Bipyramidal
Octahedral
5
0
6
0
Draw the correct Lewis dot
structure for CH2O
Draw the correct Lewis dot
structure for CH2O
What geometry can you predict
for this molecule (CH2O) ?
•Trigonal Planar
(3 bonded atoms, 0 lone pairs)
Draw the correct Lewis dot
structure for SCl2
What geometry can you predict
for this molecule (SCl2) ?
•Bent
(2 bonded atoms, 2 lone pairs)
What geometry can you predict
for a molecule with 6 atoms
bonded to a central atom and no
lone pairs present on the central
atom?
•octahedral
What type of bond exists
between chlorine (EN = 3.0) and
bromine (EN = 2.8)
•Non-polar covalent
If a substance is liquid at room
temperature, what types of bonds
do you expect hold it together?
(ionic, covalent, or metallic)
•Covalent bonds
If a substance dissolves in water
and makes a solution that
conducts electricity, what types
of bonds do you expect hold it
together?
•Ionic bonds
Write the formula for aluminum
bromide
•AlBr3
Write the formula for calcium
chlorate
•Ca(ClO3)2
Write the formula for sulfuric
acid
•H2SO4
Write the formula for iron (III)
carbonate
•Fe2(CO3)3
Which of the following is soluble
in water?
MgCrO4
•Rb2CrO4
AgCrO4
Rb2CrO4
Which of the following is soluble in
water?
Strontium oxide
iron (II) chloride
barium carbonate
lead (II) iodide
•Iron (II) chloride
Which of the following is soluble
in water?
CaSO4
•NiClO3
NiClO3
Cu3BO3
Which of the following is soluble in
water?
Magnesium cyanide
zinc chromate
calcium phosphide
gold (I) acetate
•Gold (I) acetate
What precipitate would form
from a reaction of silver nitrate
with magnesium sulfate?
•Silver sulfate
What precipitate would form
from this reaction?
CaCl2 + NaBrO3
•Ca(BrO3)2
What type of reaction is
represented below?
Element + compound  element + compound
•Single replacement
What gas will be produced if
sulfuric acid reacts with
magnesium metal?
•Hydrogen gas
What gas will be produced if
potassium chloride reacts with
oxygen gas?
•Chlorine gas (Cl2)
What set of coefficients will
balance this equation?
SrBr2 + Na2SO4  NaBr + SrSO4
• 1:1:2:1
What evidence would indicate that the
following reaction occurred?
3 Ca(OH)2 (aq) + 2 H3PO4 (aq)  6 H2O (l) + 1 Ca3(PO4)2 (s)
•A precipitate
What evidence would indicate
that the following reaction
occurred?
HNO3 (aq) + Fe (s)  H2(g) + Fe(NO3)3 (aq)
•Gas bubbles
Which of the following metals would
you likely find pure (not bonded to
another element)?
sodium
nickel
lithium
calcium
•nickel
Write a balanced equation for the
following reaction:
aqueous lithium carbonate reacts
with a zinc acetate solution
1 Li2CO3 (aq) + 1 Zn(CH3COO)2 (aq) 
2 Li(CH3COO) (aq) + 1 ZnCO3 (s)
What is the molar mass of
nitrogen gas?
•28.02 g/mol
What is the molar mass of
lithium chloride?
•42.39 g/mol
What is the molar mass of
ammonium hydroxide?
•35.06 g/mol
Calculate the mass of 0.75 moles
of sulfur
•24 g Sulfur
How many atoms are in 1.25
moles of dysprosium?
•7.53 x1023 atoms Dy
What is the mass of 2.4 x 1024
molecules of water?
•72 g of H2O
What is % of carbon in propane?
•81.68%
What percent of zinc nitrate is
oxygen?
•50.7 %
What is the empirical formula for
P4O10 ?
•P2O5
What is the empirical formula of
the a compound with the
following percent composition:
**remember the rhyme**
43.0% Sr
•SrCrO4
25.5% Cr
31.4% O
The empirical formula for a
cpmpound is CH2 and its molar
mass is 98.21 g/mol. What is the
compound’s molecular formula?
•C7H14
The empirical formula for a
cpmpound is CHBr and its molar
mass is 278.76 g/mol. What is
the compound’s molecular
formula?
•C3H3Br3