Semester I Review
ANSWERS
Semester I Review

How many sig-figs are found in each
number?
 0.345
 3005
 300
 3.002
 0.00023
3
4
1
4
2
Semester I Review

Round each number to three sig-figs.
 45678
 0.002894
 23.76
 100.5
 56.799
45700
0.00289
23.8
100.
56.8
Semester I Review

Which of the following is a mixture.
 Pure
water compound
 Clean air
homogenous mixture
 Iron (II) oxide compound
 Salt water homogenous mixture
 Carbon dioxide compound
Semester I Review

Which of the following is a chemical
change.
 Cutting
paper
 Boiling water
 Rusting iron
 Burning gasoline
physical
physical
chemical
chemical
Complete the table using the given
numbers
Symbol
X - _25__
Mass #
Atomic #
25
10
Y - 35
35
Z - _56__
56
Protons
Neutrons
Electrons
10
15
10
14
14
21
14
25
25
31
25
Semester I Review
Calculate the average atomic mass given
the following data: element Y has three
isotopes 35.0% = 23.5 amu, 55.0% = 25.0
amu and 10.0% = 26.0 amu.
 (35x23.5) + (55x25.0) + (10x26.0) = 24.6
100
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Semester I Review

25.0 grams of a given metal displaces
44.2 mL of water; what is the density of the
metal?

25.0g/44.2mL = 0.566g/mL
Semester I Review

What did each scientist contribute to the
development of the modern atom.
 Dalton
= proof of the atom
 Thomson = cathode rays are electrons
 Rutherford = dense positive nucleus,
electrons outside nucleus, atom mostly empty
space
 Milliken = mass to charge ratio of the electron
Determine if the data below is
accurate, precise, both, or neither
Trial #
Measurement
1
34.56
2
34.45
3
34.78
True Value = 34.50
Accurate
and
precise
Calculate the percent error using the average
of the measurements. (34.60 – 34.50) x100 = 0.2899%
34.50
Semester I Review
1.
2.
3.
The splitting of a nucleus is known as
___fission _____.
The combining of two small nuclei to form a
larger one is known as ____Fusion______.
Give the formula of an alpha particle and beta
particle.
4
2
He
0
1

Semester I Review
1.
Decay of polonium-218 by alpha ()
emission.
1.
2.
3.
4.
5.
218
84
Po
214
He

+ 82 Pb
4
2
Decay of carbon – 14 by beta emission
14
14

C

+
6
7N
Decay of Thorium - 232 by an electron
capture
232
  89 Ac
Th +
0
1
232
90
0
1
Semester I Review
1. The half-life of phosphorous-30 is 2.5
min. If you start with 55 g of
phosphorus-30, how many grams would
remain after 27.5 min?
 Mfinal = (55g)(.5)11 = 0.027g
Semester I Review
Calculate the specific heat of an unknown
metal, given that 25.0g of the metal lost
3570 J of energy during a temperature
change from 100.0oC to 25.0oC
 c = 3570J / (25.0g)x(75.0oC)
 c = 1.90 J/goC
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Semester I Review
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Identify each of the letters on
the graph and explain what is
occurring.
C = solid warming/cooling
D = Phase change solid to
liquid or vice versa
E = liquid warming/cooling
F = phase change liquid to
gas or vice versa
G = gas warming/cooling
G
F
E
D
C
Semester I Review
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Label the solid, liquid,
and gas regions on
the graph.
Label the triple point
and critical point
At 600oC and 90 atm,
what phase is
yummygum in? liquid
liquid
solid
Triple point
gas
Critical
point
Semester I Review
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Give the formula for the following compounds
1) iron (II) arsenide
Fe3As2
2) lead (II) sulfate
PbSO4
3) lead (IV) hydroxide
Pb(OH)4
4) copper (II) acetate
Cu(C2H3O2)2
5) beryllium chloride
BeCl2
6) ammonium chromate
(NH4)2CrO4
7) silver oxide
Ag2O
8) potassium sulfide
K2S
Semester I Review
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Give the name of the following compounds
1) NaBr
Sodium Bromide
2) Sc(OH)3
Scandium (III) Hydroxide
3) V2(SO4)3
Vanadium (III) Sulfate
4) NH4F
Ammonium Fluoride
5) CaCO3
Calcium Carbonate
6) NiPO4
Nickel (III) Phosphate
7) Li2SO3
Lithium Sulfite
8) Zn3P2
Zinc Phosphide
9) Sr(C2H3O2)2
Strontium Acetate
10) Cu2O
Copper (I) Oxide
Semester I Review
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Name the compounds
H2SO3
Sulfurous Acid
H2S
Hydrosulfuric acid
H3PO4
Phosphoric acid
HCN
Hydrocyanic acid
H3P
Hydrophosphoric acid
HBr
Hydrobromic acid
HClO
Hypochlorous acid
Semester I Review
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Give the formula for the following compounds
hydrofluoric acid
HF
hydroselenic acid
H2Se
carbonic acid
H2CO3
nitrous acid
HNO2
sulfuric acid
H2SO4
hydrobromic acid
HBr
Chlorous acid
HClO2
Semester I Review
Antimony tribromide
 Silicon difluoride
 Tetracarbon octahydride
 Dinitrogen monoxide
 Pentaphosphorous decoxide
 Sulfur hexachloride

SbBr3
SiF2
C4H8
N 2O
P5O10
SF6
Semester I Review
P2O5
 SO2
 NO2
 AsCl3
 P4H8

Diphosphorous pentoxide
Sulfur dioxide
Nitrogen dioxide
Arsenic trichloride
Tetraphosphorous octahydride
Semester I Review

Balance and classify the reactions
_2_ C8H18 + _25_ O2  _16_ CO2 + _18_ H2O

____ FeCl3 + _3__ NaOH  ____ Fe(OH)3 + _3__NaCl

_4__ P + __5_O2  _2__P2O5
_2__ Na + _2__ H2O  __2_ NaOH + ____H2
_2__ Ag2O  _4__ Ag + ____O2
____ S8 + _12_ O2  _8__ SO3
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