Download CP Chemistry Final Exam Review Sheet

CP Chemistry
Final Exam Review Sheet Fall 2010 ANSWER KEY
The multiple choice final exam is 15% of your overall final grade. To study for the multiple choice portion, it is
suggested you use this review sheet, your notes, AKS log book, handouts, textbook, and labs. On the day of the
exam, you will need to bring a #2 pencil and a calculator. A periodic table will be provided for you.
Lab Equipment/Safety
1. a) What is a hypothesis? testable, refutable explanation for an observation or a problem
b) What is a theory? A hypothesis that has been supported by repeated experiments
c) What is a law? it describes relationships in nature without exception
2. What is the difference between accuracy and precision? Accuracy means that the measurements made are
correctly (they are very close to the accepted measurement). Precision means that a series of
measurements are close to each other (you can make the same measurement more than once and get
about the same measurement each time). Note: measurements can be precise and not accurate.
Measurement and Matter
3. Use the data table below to discern whether the students’ measurements are accurate only, precise only, both
accurate and precise, or neither accurate nor precise.
Measurement 1 Measurement 2 Measurement 3 Measurement 4
Jameel
5.0 g
4.9 g
5.0 g
5.1 g
Cody
8.0 g
8.2 g
8.0 g
7.9 g
Rachel
2.0 g
12.0 g
8.0 g
20.0 g
Juan
10.0 g
9.9 g
10.1 g
9.9 g
****The accepted value of the rock’s mass is 5.0 g
a) Describe Jameel’s measurements. accurate & precise
b) Describe Cody’s measurements. precise
c) Describe Rachel’s measurements. neither
d) Describe Juan’s measurements. precise
4. a) What piece of lab equipment measures mass? electronic balance
b) What piece of lab equipment most accurately measures volume of a liquid? graduated cylinder
c) What is the SI unit to measure length? meter Mass? gram
5. a) What is the formula for density? D= m/v
(density = mass/volume)
6. a) How is the volume of a regularly-shaped object, such as a box or book, found? v = length x width x height
b) What is the name for the method by which the volume of an irregularly-shaped object is found?
water displacement method (subtract the final volume from the initial volume: V = Vfinal – Vinitial)
7. Calculate the density of an object with a volume of 25 cm3 and a mass of 50. g.
D = m/v
D = ?
m = 50. g
v = 25 cm3
D =
50. g
25 cm3
=
2.0 g/cm3 2 sig figs b/c both measurements given in the problem
have 2 sig figs. The zero in the answer is significant
b/c there IS a decimal point shown.
8. The volume of water in a graduated cylinder rose from 52.2 mL to 56.2 mL when a solid object was placed in the
water. If the mass of the object is 38.6 g, what is the density of the object?
D = m/v
D = 38.6 g =
D = ?
4.00 mL
m = 38.6 g
v = 4.00 mL
v = vfinal - vinitial
this is water
v = 56.2 mL – 54.2 mL = 4.00 mL
9.65 g/mL
3 sig figs b/c both measurements given in
the problem have 3 sig figs.
displacement
9. You are making a density column in a graduated cylinder with vegetable oil, honey, lamp oil, and water. Layer the
order of liquids that you would have in the density column from top to bottom. The following chart lists the
densities of each substance.
Liquid
Density
Lamp oil, vegetable oil, water, & honey
Vegetable Oil
0.91 g/mL
Honey
1.36 g/mL
Lamp Oil
0.80 g/mL
Water
1.00 g/mL
10. Matter is anything with mass and volume.
11. a) Which state/phase of matter is described as being tightly packed and highly organized with particles
vibrating back and forth? solid
b) Which state/phase of matter is described as having disorganized particles as far apart as possible with a
high degree of kinetic energy? gas
c) Which state/phase of matter is described as having particles that are relatively close together and “flow”
while taking the shape of the container? liquid
12. a) Fill in the blanks in the data table below.
Description
Physical or
Chemical Change?
State/Phase
Involved in Change?
Does Kinetic Energy
Increase or Decrease?
water boils
physical
liquid to gas
increase
ice melts
physical
solid to liquid
increase
water vapor condenses
physical
gas to liquid
decrease
iodine crystals sublime
physical
solid to gas
increase
13. a) A mixture that is uniform throughout is classified as a homogeneous mixture whereas a mixture that is not
uniform in appearance is known as a heterogeneous mixture.
14. Fill in the chart below listing the physical properties of each type of mixture:
Mixture Type
Appearance/Particle
Size
Heterogeneous or
Homogeneous?
Tyndall Effect
Positive or Negative?
Positive – light beam
IS visible in mixture
Suspension
largest particles;
visible with naked eye
heterogeneous
Colloid
intermediate (medium)
sized – not visible
with naked eye
without Tyndall
Effect test
heterogeneous
Positive – light beam
IS visible in mixture
no settling
Solution
smallest size particles
– not visible with
naked eye
homogeneous
Negative – light beam
NOT visible in
mixture
no settling
Is there Settling?
settles into layers
15. a) A cloudy mixture with no settling, and a positive Tyndall effect would be classified as a(n) colliod.
b) On the other hand, a mixture with no settling, no visible layers, and a negative Tyndall effect would be
classified as a(n) solution.
16) If a cough medicine reads “shake before using,” it is probably what specific type of heterogeneous mixture?
Suspension; it settled into layers so to “mix” the layers, you need to shake the mixture. Italian
salad dressing is also a good example of a suspension because you have to shake it before pouring it
onto a salad.
17. a) A type of homogeneous mixture made of two or more metals melted together is known as a(n) alloy.
b) An example of this would be brass because it is made of copper and zinc.
18. Identify the following as a chemical or physical.
a. copper reacts with oxygen to form a green patina chemical change
(new substance green patina & color change)
b. milk spoils
chemical change
(milk altered – you wouldn’t drink spoiled milk!)
c. copper compounds are blue
physical property
d. water evaporates on a hot summer day
physical change (changed from liquid to gas)
e. ice melts if not in the freezer
physical change (changed from solid to liquid)
f. fermentation of grapes to make wine
chemical change (new substance wine)
g. an iron nail rusts
chemical change (new substance rust)
h. combustion of wood
chemical change (made CO2 and H2O)
i. state of matter changes
physical change (only changed how far apart atoms are)
j. dissolving of chocolate in milk
physical change (can separate chocolate from milk)
(observation of color – color did not change)
19. What are four pieces of evidence that a chemical change is taking place?
color change
gas forms (smoke, bubbles)
precipitate formation
odor change
temperature change
20. Indicate whether the following can be separated by physical, chemical, or nuclear means.
a) atoms
nuclear
b) compounds
chemical
c) mixtures
physical
Atomic Structure
21. a) Define the term atom in your own words (do not copy the definition from the book)! An atom is the
smallest particle of an element that retains the properties of that element (still has the same boiling
point, density, etc.)
b) The atomic number of an element is based on which subatomic particle? proton
c) Which element has atomic number 8? oxygen
d) In a neutral atom, the number of protons is equal to the number of electrons.
22. Fill in the chart below concerning subatomic particles.
Subatomic Particle
Location
Charge
proton
Nucleus
+1
neutron
0 (neutral –
in nucleus
no charge)
electron
outside nucleus in
electron cloud
negative
Job of Particle
Identifies the element
determines isotopes of an
element
determines chemical reactivity
(which elements bond together to
get a full octet)
23. a) The majority of the mass of the atom is in which part of the atom? nucleus
b) The mass number is equal to the number of protons and neutrons added together. This is because the
mass of the atom is in the nucleus and the protons and neutrons are in the nucleus.
c) An atom with 11 protons, 12 neutrons, and 11 electrons would have a mass number of 23 (protons +
neutrons).
d) An atom with 11 protons, 12 neutrons, and 11 electrons would have an atomic number of 11 (# protons).
e) What would be the isotopic notation for an atom with 11 protons, 12 neutrons, and 11 electrons?
23
11
Na
24. a) An isotope has the same numbers of protons but different numbers of neutrons.
b) Examine the following isotope notation. Label the number on the top and bottom.
mass number
atomic number
c) Examine the following isotope:
13
C
6
210
90
Th
How many protons does this isotope contain? 90 How many neutrons does this isotope contain? 120
25. a) How do you determine the most common isotope of any element? Look on the periodic table for the
average atomic mass
b) What is the most common isotope of sodium? Na - 23
c) What is the most common isotope of barium? Ba - 137
26. Find the average atomic mass of Element X if 51.83% of Element X occurring in nature has a mass of 106.905
amu and 48.17% of the atoms have mass of 108.905 amu.
average atomic mass = atomic mass
x
% abundance
100%
Step 1: Perform this calculation for EACH isotope; if there are 3 isotopes then do this equation 3
times!
Step 2: Add up all the atomic masses to calculate the average atomic mass – remember this is a
WEIGHTED average (not the same as a normal average).
X1 .5183 x 106.905amu = 55.408861 amu
X2 .4817 x 108.905amu = +52.459538 amu
107.86839 amu
percentages in decimal form
107.868 amu
*need 3 places after the
decimal b/c when adding count
fewest decimal places
Identity of element X: silver
*find atomic mass closest to
amu on periodic table
27. Write the full electron configuration for the following elements.
a) titanium 1s22s22p63s23p64s23d2
28. What element has the orbital diagram below? potassium How do you know? Count arrows = atomic number
29. What element has the orbital diagram below? argon How do you know? Count arrows = atomic number
30. Draw the Lewis/Electron Dot structure for the following elements:
a) Sodium
b) Iodine
c) Aluminum
group 1A = 1 val. eso one 1 dot
group 7A = 7 val. eso 7 dots
d) Oxygen
group 3A = 3 val. eso 3 dots
group 6A = 6 val. eso 6 dots
e. Lewis/Electron dot structures show what type of electrons? Valence electrons in the valence (outermost)
shell (s and p sublevels)
*remember: group # = # valence electrons (for group A elements)
31. What is the name of the lowest, most stable energy level an electron occupies within an atom? ground state
32. What happens within an atom when an electron undergoes excitation?
excitation: lower to a higher energy level & absorb photons (energy)
de-excitation: higher to lower energy level & release (emit) a photon & visible light
33. How can the identity of an unknown be identified using the flame test? Explain. Color match – each element
has its own unique color
Nuclear Chemistry
34.
a) 239
U
92
b) 210
Po
84
c) 14
C
6
 239
Np + 01 e
93
 206
Pb + 24He
82
 14
N + 01 e
7
Is this alpha, beta, or gamma decay? beta
Is this alpha, beta, or gamma decay? alpha
Is this alpha, beta, or gamma decay? beta
35. Fill in the chart below.
Type of Decay
alpha ()
Beta Decay ()
gamma ()
Particle Emitted
Helium nucleus (42He)
0
1 e
0
(fast moving electron)
0
(made of photons)
36. a) What is radioactive decay? Radioactive decay is the spontaneous emission of radioactive particles (or
energy) from an unstable nucleus in an attempt to make a more stable nucleus.
b) What determines whether an atom is radioactive and unstable? Neutron-to-proton ratio (n0:p+ ratio)
37. What is half–life? The amount of time it takes for HALF of a radioactive isotope to decay.
38. Fusion involves atoms combining to make a larger atom whereas fission is when atoms split to make two or
more smaller atoms that are more stable.
Periodic Table
39. Mendeleev arranged the periodic table by increasing atomic mass whereas the modern periodic table is
arranged by increasing atomic number.
40. Rows on the periodic table are called period and columns are called groups or families.
41. Fill in the following chart. The first one has been done for you as an example.
Number Valence
Group Name
Group Number
Electrons
Alkali metals
1A
1 val. ealkaline Earth metals
2A
2 val. eboron group
3A
3 val. E
carbon group
4A
4 val. E
nitrogen group
5A
5 val. E
oxygen (chalcogen) group
6A
6 val. E
halogens
7A
7 val. E
noble (inert) gases
8A
8 val. E
42. Which group of metals is the most reactive group? alkali metals Why? They have 1 valence e- that can
easily be lost to gain a full octet (because it’s easier to lose 1 than gain 7 e-).
43. Which group of nonmetals is the most reactive group? halogens Why? They have 7 valence e- so they can
easily gain 1 electron to get a full octet (because it’s easier to gain 1 than to lose 7 valence electrons).
44. Which group of elements is the least reactive? noble gases Why? They have 8 valence electrons to
complete a full octet; therefore, they don’t need to bond with other atoms to gain/lose/share electrons to
acquire a full octet.
45. a) Fill in the chart below by placing a check mark by the properties that match each type of element.
Physical/Chemical
Property
Lustrous (shiny)
Brittle (shatter)
Malleable (bendable)
Conductive
Dull
Reacts with Acid and CuCl2
Gaseous
Solid
Metal
Nonmetal








b) Unknown X is lustrous, malleable, and reactive with acid. This unknown is probably a(n) metal because it
has all metallic properties.
c) Metals are located to the left of the staircase (with the exception of hydrogen) and nonmetals to the right
of the staircase. Metalloids are located on the staircase.
46. Which of the following elements is not a nonmetal? Circle all that apply.
a) calcium
b) oxygen
c) silicon
d) neon
47. What is:
a) atomic radius? the size of an atom
b) electronegativity? the ability of an atom to attract an electron to itself
c) ionization energy? the energy required to remove an electron from an atom by another atom
What happens to:
a) atomic radii across a period? decreases
down a group? increases
b) electronegativity across a period? increases
down a group? decreases
c) ionization energy across a period? increases
down a group? Decreases
48. What does electronegativity do across a period as atomic number increases? ________________________
49. What element has the highest ionization energy? ___________________ Why?
Chemical Bonding
50. What is the octet rule? The octet rule states that atoms will gain, lose, or share electrons in order to
get a full octet (8 e-) in the valence (outermost) shell of an atom.
51. An ion is a particle with an electrical charge created by the transfer (loss or gaining) of electrons.
52. What is a cation (and how is it created)? positively charged ion formed by losing of electrons
example: Ca+2 is a cation which loses two negatively charged electrons to become positively charged
53. What is an anion (and how is it created)? negatively charged ion formed from the gaining of electrons
example: N-3 is an anion which gains three negatively charged electrons to become negatively charged
54. a) Explain the difference between Mg and Mg+2.
Mg is a neutral atom with 12 protons and 12 electrons.
Mg+2 is a cation (positive ion) with 12 protons and 10 electrons (+2 means it lost 2 e-)
b) Explain the difference between Cl and Cl-1.
Cl is a neutral atom with 17 protons and 17 electrons.
Cl-1 is an anion (negative ion) with 17 protons and 18 electrons (-1 means it gained 1 e-)
55. a) Will titanium form a cation or anion? cation
b) Will sulfur form a cation or anion? sulfur
56. Examine the orbital diagram below. Will atoms of this element most likely gain or lose electrons? lose
How many electrons will be gained or lost? 1
57. Examine the orbital diagram below. Will atoms of this element most likely gain or lose electrons? gain
How many electrons will be gained or lost? 2
58. a) An atom with 7 valence electrons would most likely be in what state/phase of matter? solid/liquid/gas
b) An atom with 2 valence electrons would most likely be in what state/phase of matter? solid
c) An atom with 8 valence electrons would most likely be in what state/phase of matter? gas
59. Why do elements in the same family/group have the similar physical and chemical properties?
they have the same number of valence electrons
60. a) Fill in the chart below by placing a check mark by the properties that match each type of element.
Description
referred to as polar
most commonly referred to as nonpolar
made of metals and nonmetals
made of cations and anions
involves sharing of electrons to get full octet
involves Latin prefixes (mono-, di-, tri-, tetra-, etc)
will dissolve in water (not oil) and strongly conduct electricity
involves gaining/losing electrons to get full octet
Ionic

Covalent







61. a) Water’s chemical formula is ______________.
b) Is water polar or nonpolar? _______________________ Why?
62. Fill in the blanks in the data table below.
Compound Name
Ionic or Covalent?
Chemical Formula
calcium hydroxide
Ionic
Ca(OH)2
ammonium phosphate
Ionic
(NH4)3PO4
disilicon hexachloride
Covalent
Si2Cl6
carbon tetrafluoride
Covalent
CF4
63. Fill in the blanks in the data table below.
Chemical Formula
Ionic or Covalent?
Compound Name
C2H6
Covalent
dicarbon hexahydride
PbO
Ionic
lead(II) oxide
Sr3(PO4)2
Ionic
strontium phosphate
P2O5
Covalent
diphosphorus pentoxide
64. a) When Pb+4 and SO4-2 combine, what is the formula of the compound formed? Pb(SO4)2 because the ions
oxidation numbers reduce to make Pb+2 SO4-1.
b) When NH4+1 and CO3-2 combine, what is the formula of the compound formed? (NH4)2CO3
c) Predict the chemical formula for a compound made from a lithium ion and the oxide ion. Li2O
d) Predict the chemical formula for a compound made from a calcium ion and the chloride ion. CaCl2
65. a) What is the name of a compound made from an Fe +3 and an O-2 ion? iron(III) oxide
b) What is the name of a compound made from an Li+1 and an NO2-1 ion? lithium nitrite
66. a) How many formula units are in 5 (NH4)3PO4? 5 formula units (coefficient by itself tells)
b) Complete an atom inventory for 5 (NH4)3PO4.
Step 1: Clear parentheses by multiplying the subscript outside the parentheses by the subscripts
inside the parentheses.
5 N3H12PO4
Step 2: List each element and multiply coefficient by each subscript.
N = 15
H = 60
P = 5
O = 20
(coefficient
(coefficient
(coefficient
(coefficient
5
5
5
5
x
x
x
x
subscript
subscript
subscript
subscript
3)
12)
1)
4)
c) The name for 5 (NH4)3PO4 is ammonium phosphate.
Chemical Equations
67. Balance the following equations (in the small blanks) AND in the large blank to the right identify the type of
reaction as single displacement, double displacement, synthesis, decomposition, or combustion.
a)
1 Li2SO4
+
b)
2 Al
3 CuSO4
c)
2 KIO3
d)
2 C12H26
e)
2 H2
+
2 KI

+
1 Pb(NO3)2

+
+
37 O2
1 O2


2 LiNO3
1 Al2(SO4)3
+
+
3 Cu
3 O2
 24 CO2 + 26 H2O
2 H 2O
1 PbSO4
double displacement (all compounds)
single displacement (Al is a single element)
decomposition (one REACTANT)
combustion
synthesis (one PRODUCT)
68. Why must chemical equations be balanced? Must obey Law of Conservation of Matter/Mass
69. a) What is a reactant? The substances you START with in a chemical reaction; to the left of the arrow
b) What is a product? The substances you END with (make/produce) in a chemical reaction; to right of
arrow
70. Write a balanced equation from the sentence below and identify the type of reaction in the blank.
Hydrogen gas reacts with oxygen gas to produce dihydrogen monoxide. synthesis (one PRODUCT)
H2
O2
di = 2 H mono = 1 oxygen
diatomic
2 H2
diatomic
+
1 O2
covalent (2 nonmetals) so do NOT cross over anything or look up oxidation #s

2 H2 O
**. What did Rutherford conclude from his Gold Foil Experiment?
o
o
o
There is a dense center of the atom called the nucleus.
The nucleus is positively charged.
The atom is mostly empty space.