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Name: _________________________________________ Date: ________________ Period: ___________
CP Chemistry Semester 1 Final Test Review
CHAPTERS 1 & 2: Scientific Method, Density, Metric Conversions, Accuracy/Precision, Significant Figures
1. Know the steps in the scientific method.
A. Define each of the steps.
a) observation, b) hypothesis, c) experimentation or testing, d) collecting or recording data, e)
drawing conclusions, f) theory, g) scientific law
B. What is the difference between a theory and a scientific law?
Scientific Law: Describes a relationship in nature that is supported by many
experiments. Usually taken as “fact” by most scientists.
Theory: An explanation supported by many experiments, but is still subject to
new experimental data, and can be modified
C. What is the difference between a hypothesis and a theory?
Hypothesis: A tentative, testable statement or prediction about what has been
observed. An educated guess.
Theory: An explanation supported by many experiments, but is still subject to
new experimental data, and can be modified
2. Know the symbol and the power of 10 for the following metric prefixes:
A. Mega M 106
D. deka da
101
G. centi cm
3
0
B. kilo
k 10
E. base (m, s, g) 10
H. milli m
C. hecto h 102
F. deci
d
10-1
I. micro µ
3. Metric Conversions: Give the value of the following in the units indicated.
a.
b.
c.
d.
6.92 cm = ___0.0692___ m
8 Mg = _______8,000___ kg
35 km = ___3,500,000___ cm
520 ml = _____0.52_____ L
e.
f.
g.
h.
10-2
10-3
10-6
934 µm = ___0.934____ mm
550 mL = ____0.55____ L
6,450,000 mg = _6.450_kg
0.075 g = ___75____ mg
Density Problems: Calculate the following using correct units and significant digits.
4. A metal has a volume of 8.4 mL and a mass of 32.0 g. What is its density?
3.8 g/mL
5. A solid object has a density of 7.00 g/mL and a volume of 12.0 mL. What is its mass?
84.0 g
6. An object has a density of 9.0 g/mL and a mass of 41.2 g. What is its volume?
7. Be able to read and interpret data off a line graph.
4.6 mL
30
20
10
Mass in grams
40
50
MASS v. VOLUME FOR SAMPLES OF
SUBSTANCE X
5
10
15
20
Volume in mL
25
30
35
a. If the mass is 30 grams,
what is the volume? 15 mL
b. What is the mass if you
have 10 mL of substance X?
20 g
c. Calculate the approximate
slope of the line. y/x
Slope = (30-20)/(15-10) = 2
d. Calculate the approximate
density of the substance X.
density = slope of mass v.
volume graph! = 2 g/mL
(calculated in question c.)
8. Know the correct number of significant figures to report in calculations.
Report these answers to the correct number of significant figures.
A.
3.461 + 14.9 + 5.26331 = 23.6 (1 decimal place)
B. 4605.32 ÷ 6.5 = 710 (2 sig figs)
9. Know the difference between Precision and Accuracy.
Identify each of the targets to the right as
ACCURATE and/or PRECISE.
Accuracy: How closely individual
measurements agree with the correct
or true value
Precision: How closely individual measurements agree (repeatibility)
Left bullseye is neither precise nor accurate; middle is precise and accurate; right
bullseye is precise but not accurate.
CHAPTER 3: Matter: Physical and Chemical Changes
10. Explain the difference between a homogeneous mixture (solution) and a heterogeneous mixture. Give an
example of each.
Heterogeneous Mixture : A mixture that does not blend smoothly throughout – ex. sand and water
Homogeneous Mixture: A mixture that has constant composition throughout – ex. salt and water
11. Explain the difference between a physical change and a chemical change. Give an example of each.
Physical Change : A change in which no new substances are formed – melting, boiling, distillation,
crystallization, dissolving
Chemical Change: New substances are formed – combustion, burning, decomposition
12. Conservation of mass problems (mass of reactants = mass of products):
a.
Water is decomposed into hydrogen and oxygen. If 10.0 grams of hydrogen and 79.5 grams of
oxygen are collected, how much water did you start with?
10.0 g hydrogen + 79.5 g oxygen = 89.5 g product = 89.5 g reactant (water)
b.
If 25 grams of sodium reacts with chlorine to form 99 grams of salt (NaCl). How many grams of
chlorine reacted?
Reactants: 25 g sodium + X g chlorine
Products: 99 g salt (sodium chloride)
25 g + X g = 99 g
X = 99 g -25 g = 74 g chlorine
CHAPTERS 4 & 25: The Atom and Nuclear Chemistry
13.
Which part of the atom has most of the mass but very little volume?
The nucleus contains the protons and neutrons which make up most of the mass of the
atom. The size of the nucleus is very small compared to the rest of the atom.
14.
15.
What are the charges and masses of protons, electrons, and neutrons?
symbol
mass (amu)
charge
proton
p+
1 amu
1+
neutron
n0
1 amu
0
electron
e-
~0 amu
1-
What are the differences in the atomic number, atomic mass and mass number?
Atomic
number
Definition
The number of protons in an element.
It determines what element it is. In a
neutral atom, atomic number also
equals the number of electrons. ON
THE PERIOIC TABLE.
How to calculate
# p+ (or # e- in a neutral
atom)
Mass
number
The mass of a specific isotope
p+ + n0
Atomic
mass
The weighted average mass of all
naturally occurring isotopes. ON
THE PERIODIC TABLE.
Weighted average of
mass number and
percent abundance of all
isotopes.
16.
What is the definition of an isotope?
An isotope is an element with different number of neutrons.
17.
Why do isotopes of the same element (ex. carbon-12, carbon-13, carbon-14) have different mass
numbers?
Isotopes of the same element have different mass numbers because they have different
numbers of neutrons (mass number = #p+ + #n0)
18.
Which isotope is the standard for the atomic mass unit (amu)?
12 amu = mass of 1 carbon-12 atom (1 amu = 1/12 carbon-12 mass number)
19.
Calculate the number of protons, neutrons and electrons in an isotope when given its mass number
and atomic number.
Element
atomic
number
mass
number
protons
neutrons
electrons
Isotope name
(using name)
Copper (Cu)
29
64
29
35
29
Copper-64
Neon (Ne)
10
21
10
11
10
Neon-21
Zinc (Zn)
30
65
30
35
30
Zinc-65
Magnesium
(Mg)
12
26
12
14
12
Magnesium26
Isotope name
(using
symbol)
20.
In a chemical reaction, what changes in the atom and what is formed?
Electrons are shared, gained or lost and a new compound is formed
21.
In a nuclear reaction, what changes in the atom and what is formed?
The nucleus of an atom changes and a new element is formed
22.
Use the following data table on the isotopes of element “X” to answer Questions A&B listed below:
Percent
CALCULATE:
Isotope Mass in amu
Abundance %
(Mass number) X (% abundance)/100
X-20
19.992
90.48
18.089
X-21
20.994
0.2700
0.0566
X-22
21.991
9.250
2.861
Weighted average atomic mass
20.179 amu
(SUM OF CALCULATED VALUES):
Weighted avg. atomic mass = (Mass x
)X-20 + (Mass x
)X-21 + (Mass x
A. What is the weighted average atomic mass of element “X”?
)X-22
20.18 amu
B. Using the periodic table what is the identity and atomic number of element “X”? Neon, 10
23.
Assume the following three isotopes of element Z exist: Z-248, Z-252, and Z-259. If the atomic
mass of Z is 258.63 amu, which of these isotopes is most abundant?
Since the atomic mass is the weighted average, the most abundant will be the isotope with the
mass number closest to the atomic mass: Z-259
24.
Why does radioactivity occur? Due to spontaneous decay of an unstable nucleus
25. Know that the forms of natural radioactivity are alpha, beta, and gamma.
symbol
Alpha α
Beta β
Gamma γ
26.
Mass (amu)
4
0
0
charge
Damage caused
2+
Stopped by clothing so no
skin damage. Ingested or
inhaled. Can cause lung
cancer (i.e., radon gas)
1-
Can penetrate several mm
into skin or be ingested
by eating contaminated
food. Can cause burns,
tissue damage and
radiation sickness.
0
Can pass through your body.
Causes cancer, radiation
sickness, tissue and
organ damage.
Which form of radiation has the lowest energy (ex. can be stopped by paper)? Alpha
Which form has the highest energy (ex. will pass through several feet of concrete)? Gamma
27. What particles would you use to balance the following nuclear reactions?
a.
(a)
(b)
(c)
b.
(a)
(b)
(c)
C.
(a)
(b)
(c)
28. What is the difference between nuclear fusion and nuclear fission?
In nuclear fusion, two smaller elements collide and form a larger element.
In nuclear fission, a neutron hits a large nucleus and the nucleus splits into two
smaller elements.
29. Identify the following as fission or fusion reactions and fill in the blank:
 _______ +
A.
fusion

B.
fission
30. What is half – life?
Half life is the time it takes for half of a radioactive element to decay into another
element.
31. Know how to solve half-life problems: Na- 24 has a half-life of 15 hours. How long will it take for a
sample to decay to 12.5% of its original mass
100%/12.5% is 3 half lifes
3 x 15 hours = 45 hours
32. Write and balance the following equations:
A.
Radon-222 undergoes alpha decay (loses
Radon-222 
+ Polonium-218
B.
)
Uranium-238 undergoes beta decay
Uranium-238 
+ Np238
CHAPTER 5: Electrons in Atoms
33. Give the (1) electron configuration (2) noble gas shorthand and (3) orbital filling diagram for the
following elements.
a. Sulfur
(atomic number 16)
1s22s22p63s23p4
[Ne]3s23p4
1s
b. Copper
2s
2p
(atomic number 29)
3s
3p
1s2 2s2 2p6 3s2 3p6 4s2 3d9
[Ar]4s2 3d9
1s
2s
2p
3s
3p
4s
3d
34. Give the Lewis electron dot diagrams for the following elements.
35. Know how to convert between wavelength and frequency (c = 3.00 x 108 m/s).
a. What is the wavelength of electromagnetic radiation having a frequency of 5.00×1012 Hz?
c = λѵ
λ = (3.00×10 m/s)  (5.00×1012 1/s)
λ = 6.00×10-5 m
8
b. What is the frequency of electromagnetic radiation having a wavelength of 3.33×10-8 m?
c = λѵ
ѵ = (3.00×10 m/s)  (3.33×10-8 m)
ѵ = 9.00×1015 Hz or 9.00×1015 /s
8
CHAPTER 6 – The Periodic Table
36. Periodic Table Organization
A. The periodic table is arranged by increasing atomic number.
B.
Rows on a periodic table are called periods. Columns on a periodic table are called groups or
families.
C.
Properties of elements in the same (period or group) change as you move left to right or right
to left and repeat as you move from one to the next.
D.
Properties of elements in a (period or group) are similar.
E.
All atoms of the same element contain the same number of what particle? Protons
F. Identify the location of these groups or families: Alkali Metals (Group 1A) Alkaline Earth
Metals (Group 2A) Halogens Group 7A) Noble Gases (Group 8A)
G.
Given the electron configuration, identify the element, period and group on the periodic table:
[Ne]3s23p2
[Kr]5s2
[Ne]3s23p6
[Ar] 4s1
[Ne]3s23p5
Element
Si
Sr
Ar
K
Cl
Period
3
5
3
4
3
Group
4A
2A alkaline
earth metal
8A noble gases
1A alkali
metals
7A halogens
Metal/ nonmetal/
metalloid?
Metalloid
Metal
Nonmetal
Metal
Nonmetal
37. Periodic Table Trends
Know the definitions of each property and the general trends by group and period for:
Electronegativity: Attraction of an atom for electrons
Which element has the highest electronegativity?
Fluorine
Which group/family has ZERO electronegativity? Noble Gases
Ionization Energy: Energy required to remove an electron from an atom
Atomic Size (atomic radius): Distance between the center of an atom to the outer edge of the
electron cloud (measured as half the distance between two nuclei)
Ionic size (ion radius): Distance between the center of an ION (which has lost or gained electrons)
to the outer edge of the electron cloud
A.
Identify which of the element in each pair has the LARGER atomic radius:
a. K and Sc
B.
b. Cl and I
c. Ca or Ga
d. Se or O
List the elements in order of INCREASING electronegativity:
a.
O, S, Se: Se, S, O
b. Al, Cl, P: Al, P, Cl
c. Ca, Mg, Sr: Sr, Ca, Mg
Electronegativity and
Ionization Energy
Atomic Size and
Ionic Size
Electronegativity and Ionization Energy
Atomic Size and Ionic Size
CHAPTER 8 – Ionic Compounds
38. An ion is an atom that has gained or lost electrons in order to become more stable; by achieving the
noble gas configuration.
39. Complete the table for the ATOMS and IONS of these elements:
Element
Element
Symbol
Atomic
Number
# Valence
Electrons in the
Atom
Total Number of
Electrons in an
Atom
Total Number of
Electrons in an Ion
Ion symbol
Magnesium
Mg
12
2
12
10
Mg2+
Oxygen
O
8
6
8
10
O2-
Phosphorus
P
15
5
15
18
P3-
Aluminum
Al
13
3
13
10
Al3+
Iodine
I
53
7
53
54
I-
Lithium
Li
3
1
3
2
Li+
40. An ionic bond forms between what types of elements? A metal and a nonmetal
An ionic bond is the attraction between positively charged metal cations and negatively charged
anions.
In an ionic bond, electrons are transferred from the metal (cation) to the nonmetal (anion).
What is the structure of a solid ionic compound? Crystal lattice (alternating positive and negative
ions packed closely together in a crystalline structure)
What are properties of ionic compounds? Hard, brittle, very high melting points, can conduct
electricity if dissolved in water or melted
41. A chemical formula tells you how many of each atom are in the compound, as indicated by
subscripts.
MgCl2 means 1 magnesium and 2 chlorine atoms are in the compound.
42. Complete the tables below:
Compound Name
Chemical Formula
Iron (III) Sulfate
Fe2(SO4)3
Nickel (III) chloride
NiCl3
Aluminum Sulfide
Al2S3
Beryllium fluoride
BeF2
43. What is the charge of the manganese ion in each of the compounds listed below?
a. MnSO3
B. MnPO4
C. Mn3P2
D. MnO2
2+
23+
32+
3Mn SO3
Mn PO3
Mn P
Mn4+ O2-