Download midterm exam review

MIDTERM EXAM REVIEW
PRACTICE QUESTIONS & PROBLEMS -- These are just sample problems; the midterm will
cover all topics that have been taught this year in Chemistry GT. Review past tests, test review
sheets, classwork and homework.
1. Label each substance below as an element, compound, homogeneous mixture or
heterogeneous mixture.
a air
b. salt
c. concrete
d. nitrogen
a. homogeneous
b. compound
c. heterogeneous
d. element
2 Determine whether each process below is a physical or chemical change:
a salt dissolving in water
b. wax melting
a. physical
b. physical
c. paper burning
d. baking a cake
c. chemical
d. chemical
3. Determine the number of significant figures in each measurement below. Then change each
to scientific notation:
a. 0.001350g 6 sig figs, 1.35 x 10-3 g
b. 20.1650g
6 sig figs, 2.0165 x 101 g
4. Fill out the chart below. Then make the metric conversion below:
1000 mm = 1 m
10 dg = 1 g
100 cJ = 1 J
1 kPa = 1000 Pa
5. Element Y has three isotopes. The atomic mass and abundance of each isotope is given below.
Find the average atomic mass of Element Y.
Isotope 1
42.67amu
29.5% = 12.59
Isotope 2
45.44amu
62.1% = 28.22
Isotope 3
49.99amu
8.4% = 4.20
____45.01 amu____
6. Determine the moles of Aluminum if you have 46.5g
46.5 g x
1 mol Al
 1.72moles Al
26.98 g Al
7. Label each substance below as ionic or covalent. Write the formula for each, and determine
the molar mass (formula mass) of one mole of each.
a
barium fluoride
Ionic
BaF2
175.31 g/mol
b dinitrogen pentoxide
Covalent
N2O5
108 g/mol
c. iron (III) hydroxide
ionic
Fe(OH)3
106.85 g/mol
C5H8O
84 g/mol
d pentacarbon octahydrogen covalent
monoxide
8. What is an ionic bond? How is it different from a covalent bond?
Ionic-metal with non-metal, transfer of electrons
Covalent-2 non-metals, sharing of electrons
9. 1.43x1024 atoms of boron is how many moles?
1 mole B
1.43x10 24 atoms B x
 2.38 moles B
6.02 x 10 23 atoms B
10. Complete the table below:
Compound
Formula
Geometry/Shape
Angle
Polar?
CS2
Lewis Diagram
Structural Diagram
linear
180
Nonpolar
NBr3
Pyramidal
107
Polar
bent
105
polar
Carbon
disulfide
nitrogen
tribromide
Each Br should have 3 lone
pairs.
H2O
dihydrogen
monoxide
11. Complete the table for the elements below:
Element
80
Br
Xe
Barium-141
Protons
35
54
56
Neutrons
Electrons
45
35
77
54
85
56
Noble Gas Notation
Electron Configuration
# of
occupied
energy
levels
Periodic Table
Group
[Ar]4s23d104p5
4
halogens
[Kr]5s24d105p6
5
Noble gasses
[Xe]6s2
6
Alkaline earth
metals
12. Complete the table for the ions below:
Ion
Formula
Protons
sodium ion
Na+1
Dot
Diagram
Neutrons
Electrons
11
12
10
8
10
Oxide
O-2
8
Zinc ion
Zn+2
30
35
28
Anion or
Cation?
Cation
Anion
Cation
13. What do members of the same periodic table group have in common? What do members of
the same period have in common?
Groups-same # of valence electrons, similar chemical properties/reactivity
Periods-same # of principal energy levels, same amount of shielding
14. Define electronegativity:
The ability of an atom to attract electrons when in a bond
Choose the element below with the greatest electronegativity:
a copper or bromine Bromine
b silicon or lead Silicon
15. Define ionization energy.
The energy required to remove an electron
Choose the element below with the greatest ionization energy:
a copper or bromine Bromine
b silicon or lead Silicon
16. Choose the element below with the greatest atomic radius:
a copper or bromine copper
b silicon or lead lead
17. Write out the correct orbital diagram for oxygen in its ground state.
18. Write the nuclear reactions below:
a.
204
Hg decomposes and releases an alpha particle
204 Hg  4He  200Pt
80
2
78
b. 140Ba decomposes and emits beta decay with gamma emission
140 Ba  0 e 0 140La
56
1 0
57
19. The half life of astatine is 8 1/2 hours. What mass of a 300.0g sample of astatine will remain
after 34 hours?
Time (hrs) 0
8.5
17
25.5
34
Mass
300.0 g 150.0 g
75.0 g
37.5 g
18.75 g
20. List the diatomic elements.
Br2, I2, N2, Cl2, H2, O2, F2
21. What are the quantum numbers for each of the 4 electrons in Beryllium?
N
l
ml
ms
1
0
0
+1/2
1
0
0
-1/2
2
0
0
+1/2
2
0
0
-1/2
22. Complete the following nuclear equation:
244U

4
2
He +
240Th
What type of radiation is this? ___alpha_____________________
23. If a piece of metal has a mass of 36.30 g and a volume of 45 L, what is its density?
D=m/v
D=36.30 g/45 L
D=0.81 g/L
24. What will the principal quantum number and the angular momentum quantum number be
for the last electron added in Krypton?
n=4, l=1
25. What is the frequency of red light with a wavelength of 692 nm?
(1 m = 109 nm, speed of light = 3.00×108 m/s)

c

3.00 x10 8 m/s
692 x 10 -9 m
  4.34 x 1014 s -1
