Chemistry 121
Worksheet 4 Notes
1.
Name: (a)
Oregon State University
Dr. Richard L Nafshun
Ca(NO3)2
calcium nitrate
(b)
AlN
aluminum nitride
(c)
Al2O3
aluminum oxide
(d)
NaCN
sodium cyanide
(e)
(NH4)2S
ammonium sulfide
(f)
Na2S
sodium sulfide
(g)
NH4OH
ammonium hydroxide
(h)
CaO
calcium oxide
(i)
KBr
potassium bromide
(j)
MgSO4
magnesium sulfate
(k)
NiCl2
nickel(II) chloride
(l)
PbS2
lead(IV)sulfide
(m)
CuCl
copper(I) chloride
(n)
CuCl2
copper(II) chloride
(o)
Fe2O3
iron(III) oxide
(p)
2.
3.
FeO
iron(II) oxide
Give the chemical formulae for the following ionic compounds:
(a)
aluminum sulfide
Al2S3
(b)
sodium sulfide
Na2S
(c)
sodium sulfate
Na2SO4
(d)
sodium hydroxide
NaOH
(e)
aluminum cyanide
Al(CN)3
(f)
calcium nitrate
Ca(NO3)2
(g)
cesium phosphate
Cs3PO4
(h)
cerium(III) chloride
CeCl3
(i)
lithium acetate
LiCH3COO
(j)
copper(II) carbonate
CuCO3
(k)
iron(II) phosphate
Fe3(PO4)2
(l)
iron(III) oxide
Fe2O3
Consider a red light that has a wavelength of 710.2 nm. Express this wavelength in
cm. Express this wavelength in km. Express this wavelength in inches.
 1m   100cm 
710.2 nm 

 = 7.102 x 10-5 cm
9
 1x10 nm   1m 
 1m 
7.102 x 10-5 cm 

 100cm 
 1km 

 = 7.102 x 10-10 km
1000
m


 1inch 
7.102 x 10-5 cm 
 = 2.796 x 10-5 inch
 2.54cm 
4.
A student measures a mass to be 2.55 x 103 kg. Express this mass in mg.
 1000 g   1000mg 
 
 = 2.55 x 109 mg
2.55 x 103 kg 
 1kg   1g 
5.
What is a heterogeneous mixture?
A mixture that is different throughout.
What is a homogeneous mixture?
A mixture that is the same throughout.
How many elements are there?
About 112 to 114.
Approximately how many compounds have cataloged and characterized?
About 17 million.
Is heptane one of them? Yes. C7H16.
Is aluminum chloride one of them? Yes. AlCl3.
6.
Determine the number of protons, neutrons, and electrons in each of the following:
Species
187
Os
Au
198
Au3+
198
Au+
210
Pb
210
Pb2+
7
Li
7 +
Li
16
O
16 2O
18
O
18 2O
19
F
19 F
238
U
198
7.
76
79
79
79
82
82
3
3
8
8
8
8
9
9
92
e-
n
111
119
119
119
128
128
4
4
8
8
10
10
10
10
146
76
79
76
78
82
80
3
2
8
10
8
10
9
10
92
List three isotopes of hydrogen. Identify the number of protons, neutrons, and
electrons in each. Identify the number of protons, neutrons, and electrons in 1H+.
Species
1
H
2
H
3
H
1 +
H
8.
p
p
1
1
1
1
n
0
1
2
0
e1
1
1
0
Write the formula and name a compound composed of calcium and fluorine.
CaF2 is calcium fluoride
9.
Write the formula and name a compound composed of aluminum, sulfur, and
oxygen.
Al2(SO4)3 is aluminum sulfate
10.
Natural strontium consists of the following isotopes:
Isotope
Strontium-84
Strontium-86
Strontium-87
Strontium-88
Molar Mass, u
83.913
85.909
86.909
87.906
Percent Abundance
0.56
9.86
7.00
82.58
Calculate the molar mass of strontium.
The molar mass is the weighted average:
Molar mass
=
(83.913 g/mol)(0.0056) + (85.909 g/mol)(0.0986) +
(86.909 g/mol)(0.070) + (87.906 g/mol)(0.8258)
=
87.634 g/mol