Download Review 3rd Qtr KEY

REVIEW: 3rd QUARTER
Name:
KEY
****MUST SHOW ALL CALCULATIONS***
CHAPTER 1 & 2 : MATTER & MEASUREMENT
1.
Complete the following table
Chemical or Physical Property
Extensive or Intensive Property
CHEMICAL = 2
PHYSICAL = 3
EXTENSIVE = 1
INTENSIVE = 4
Melts at 68.0°C
Corrosive
2.2 lbs
Decomposes in air
Magnetic
2.
Osmium is the densest element with a density of 22.57 g/cm3. Find the mass of a 56.2 cm3
sample of osmium.
1268 grams
20 mL = ______________cm3
1mL = 1cm3
3.
Convert
4.
0.0054 weeks is equivalent to how many minutes?
5.
Indicate the # of significant figures then round each to the # of significant figures indicated.
12.5
54.4 minutes
has __3__ significant figures & rounded to 2 significant figures is
12
0.0010 has __2__ significant figures & rounded to 3 significant figures is 0.00100 or 1.00 x 10-3
3.5 x 1023 has __2___ significant figures & rounded to 4 significant figures is 3.500 x 1023
6.
Given calculations with the calculator answer, write the answers with the appropriate # of
significant figures.
13.0 + 46.10
=
59.1
The answer should be 59.1
227 x 0.3
=
68.1
The answer should be 70
CHAPTER 3 & 22 : ATOM & NUCLEAR CHEMISTRY
7.
Complete the table for the following isotopes.
SYMBOL
Atomic #
Mass #
# of protons
# of neutrons
# of electrons
Zn
20
65
74
34
40
21
18
TOTAL
102
220
102
118
102
8.
What one number identifies an element? ___________
9.
How many magnesium sulfate molecules are in 25.0 g?
1.25 x 1023 molecules Mg(SO4)
10. Complete the following nuclear equations
a) Decay of polonium-218 by alpha () emission.
b) Decay of carbon-14 by beta () emission
11. Carbon-14 has a half-life of 5,730 years. If a plant contained 2.0 g of 14C when it died, how much
is left after 34,380 years?
mf = 0.03125 mg
12. What is an ISOTOPE? Give examples
CHAPTER 4: ELECTRON ARRANGEMENT
13. Explain why chromium’s electron configuration is [Ar] 4s13d5 instead of the expected
configuration of [Ar] 4s23d4
Filled & ½ filled orbital’s are more stable.
14. Complete the following question based upon Cobalt (#27)
a) Give the noble gas electron configuration for this element: _________________________
b) What are the quantum numbers for this element? _____, _____, _____, _____
c) How many unpaired electrons does this atom have?
3
d) How many outer-shell electrons (valence electrons) does an atom contain? 2
e) How many inner-shell electrons (core electrons) does an atom contain? 25
15. List the quantum numbers for Cadmium (#48): _____, _____, _____, _____
16. What element is represented by the quantum number 5, 3, 1, +1/2: _________________
17. Calculate the wavelength if the frequency is 2.5 x 105 Hz.
1200 m
18. Find the energy of a photon if frequency is 7.31 x 1014 Hz.
4.84 x 10-19 J
CHAPTER 5 - PERIODICITY
19. Circle the atom with the LARGER radius.
a) Ra
or
N
b)
Ne or
Xe
20. Circle the particle with the LARGER radius.
a) Cl
or
Cl –
b)
Mg
or
Mg2+
21. Circle the atom with the HIGHER first ionization energy.
a) Li
or
Cs
b)
Ba
or As
22. Magnesium reacts with oxygen to produce the ionic solid magnesium oxide (MgO). Which other
elements would you predict would react with oxygen in a similar reaction? Explain
Elements: Be, Ca, Sr, Ba, Ra
Alkaline Earth Metals because they all have the same number of valence electrons
CHAPTER 7 – NOMENCLATURE & FORMULA WRITING
23. Name the following compounds
a) KNO3 ____________________________
b) HBr ____________________________
c) SO3 ______________________________
d) FeCl3 ___________________________
24. Find the percentage composition of the anhydrate in ZnSO4 • 7H20
56.14 % Anhydrate
CHAPTER 6 - MOLECULAR GEOMETRY
25. Ionic bonds are the electrostatic attraction between oppositely charged atoms. What
determines their strength? Explain
1) Magnitude (Product) of Charge - Increase #  Increase bond strength
2) Atomic Radius – Increase size  Increase bond strength
26. Which ionic compound has the GREATER ionic bond strength, LiCl
or NaCl ?
LiCl
27. Which ionic compound has the GREATER ionic bond strength, BaS or K3N ?
BaS
28. Ionic compounds generally have (lower or higher) melting and boiling points.
29. Molecular compounds generally have (lower or higher) melting and boiling points.
30. Identify the intermolecular forces involved for each compound below and circle the compound
with the stronger intermolecular forces for each pair?
For each pair,
circle the compound with the
strongest IMF
INTERmolecular Forces Involved
NF3
L.D.
D.D. ( EN = 4-3 = 1)
N2
L.D.
↑ size  ↑ L.D.
CH3Cl
L.D.
D.D. (asymmetrical)
NF3 or PF3
N2 or O2
CH3Cl or H2O
PF3
L.D.
D.D. ( EN = 4-2.1 = 1.9)
O2
L.D.
H2O
L.D.
D.D. (asymmetrical)
Hydrogen Bonding
31. Why do atoms form chemical bonds? to lower their potential energy & to become stable
32. For each of the following molecules, draw the Lewis electron dot diagram, give the shape, and
state whether the molecule is polar or nonpolar.
Lewis Diagram
Molecular Shape
Molecular Polarity
SiO2
Linear
Nonpolar
AsF5
Trigonal
Bipyramidal
Nonpolar
33. Determine if the following molecules are polar or nonpolar.
TeCl2
bent
BCl3
Cl
Te
Cl
Cl
nonpolar
CH2Cl2
C
polar
Cl
NONPOLAR
tetrahedral
Cl
B
Cl
POLAR
trigonal planar
H
POLAR
Cl
H
nonpolar