General Chemistry
Summer 2001

Review Assignment #1

Chapter 1
 

4.

a) air: homogeneous mixture

b) tomato juice: heterogeneous mixture

c) iodine crystals: pure substance (it is an element)

d) a nickel: homogeneous mixture (nickels are composed of an alloy that is 75% copper and 25% nickel; metallic alloys are homogeneous mixtures)
 
 

14. Chemical & Physical Properties of Zinc

Physical properties:
· silver grey metal
· melting point = 420o C
· hardness = 2.5
· density = 7.13 g/cm3
Chemical properties:
· reacts with dilute sulfuric acid to yield hydrogen and dissolves
· reacts with oxygen to give zinc oxide


24.

a)


 

Ruthenium will not float since it has a density greater than that of water.
 

b)
 


c)

26.
 

 

The measured density is consistent with the tabulated value

 
b)

 


c) The volume of the sphere is:


 

Thus, the mass of the sphere is:

 

 


32.

a) mass of a coffee can: a measured value (inexact)
b) number of students in a class: an exact value
c) the temperature at the surface of the sun: a calculated value (inexact)
d) mass of a postage stamp: a measured value (inexact)
e) the number of mL in a cubic meter: exact value (it is derived from the definitions of these units)
f) average height of a population: a measured value (inexact)
  34.
a) 1.689 ´ 10-3 km (4 significant figures)

b) 0.0234 m2 (3 significant figures)

c) 7,194,300 cm (5 significant figures)

d) 435.983 K (6 significan figures)

e) 204.080 g (6 significant figures)


36.

a) 1.44 ´ 105

b) 9.75 ´ 10-2

c) 8.90 ´ 105

d) 6.76 ´ 104

e) 3.40 ´ 104

f) -6.56 ´ 100

38.
 
a)

 
b)

 
c)

 
d) 

 

44.
 
 
a)

 
b)

 
c)

 
d) 

 
e)
 
f) 

 

49. To answer this problem, you have to realize that the volume of the ingot is the same as the volume of the drawn wire. You can get the volume of the ingot using the mass and density information provided in the problem. The volume of the wire is given by the formula for the volume of a cylinder, V = pr2 h, where h is the height of the cylinder, or in this case the length of the wire. So,

 


 

To convert this to feet,
 


69. This problem can be solved with a creative application of units

a)
 

 
b)
 
 

c)

 


d)
 

Chapter 2
 

14.
 
 
  nuclide
protons
neutrons
a)
 phosphorus-32
15
17
b)
 chromium-51
24
27
c)
 cobalt-60
27
33
d)
 technetium-99
43
56
e)
 iodine-131
53
78
f)
 thallium-201
81
120

 

16.
 
Symbol
46Ti
103Rh
34S
127Te
88Sr
Protons
22
45
16
52
38
Neutrons
24
58
18
75
50
Electrons
22
45
16
52
38
Atomic No.
22
45
16
52
38
Mass No.
46
103
34
127
88

 

22.

 
carbon:             non-metal

silicon:              metalloid

germanium:     metalloid

tin:                     metal

lead:                 metal