Name: 
 

Gen Chem Ch. 2 Online Practice Exam


Multiple Choice
Identify the choice that best completes the statement or answers the question.
 

 1. 
All of the following are steps in the scientific method except
a.
observing and recording data.
b.
forming a hypothesis.
c.
discarding data inconsistent with the hypothesis.
d.
developing a model based on experimental results.
 

 2. 
Which of the following observations is quantitative?
a.
The liquid turns blue litmus paper red.
b.
The liquid boils at 100ºC.
c.
The liquid tastes bitter.
d.
The liquid is cloudy.
 

 3. 
Which of the following observations is qualitative?
a.
A chemical reaction was complete in 2.3 seconds.
b.
The solid had a mass of 23.4 grams.
c.
The pH of a liquid was 5.
d.
Salt crystals formed as the liquid evaporated.
 

 4. 
A statement that can be tested experimentally is a
a.
variable.
c.
generalization.
b.
model.
d.
hypothesis.
 

 5. 
A theory is best described as a
a.
series of experimental observations.
b.
generalization that explains a body of known facts or phenomena.
c.
scientifically proven fact.
d.
testable statement.
 

 6. 
A plausible explanation of a body of observed natural phenomena is a scientific
a.
control.
c.
law.
b.
experiment.
d.
theory.
 

 7. 
A theory is accepted as the explanation of an observed phenomenon until
a.
one study contradicts the theory.
b.
repeated observations conflict with the theory.
c.
a new method is discovered.
d.
a leading scientist declares that it is invalid.
 

 8. 
Standards of measurement are chosen because they
a.
can be related to everyday objects.
b.
are reproducible in another laboratory.
c.
cannot be destroyed by any common physical or chemical means.
d.
are easily changed.
 

 9. 
Which of these statements does not describe a measurement standard?
a.
Measurement standards avoid ambiguity.
b.
Measurement standards must be unchanging.
c.
A standard can be easily changed to suit the experiment.
d.
Confusion is eliminated when the correct measurement is applied.
 

 10. 
Which of these statements about units of measurement is not true?
a.
A unit compares what is being measured with a previously defined quantity.
b.
A unit is usually preceded by a number.
c.
Measurements can be compared without knowing their units.
d.
The choice of unit depends on the quantity being measured.
 

 11. 
All of the following are examples of units except
a.
mass.
c.
gram.
b.
kilometer.
d.
ounce.
 

 12. 
Which of these is not an SI base unit?
a.
kilogram
c.
liter
b.
second
d.
Kelvin
 

 13. 
The SI base units for length and time are
a.
centimeter and second.
c.
centimeter and hour.
b.
meter and hour.
d.
meter and second.
 

 14. 
The metric unit for length that is closest to the diameter of a pencil is the
a.
micrometer.
c.
centimeter.
b.
millimeter.
d.
decimeter.
 

 15. 
The symbol mm represents
a.
micrometer.
c.
milliliter.
b.
millimeter.
d.
meter.
 

 16. 
The symbols for units of length in order from largest to smallest are
a.
m, cm, mm, km.
c.
km, mm, cm, m.
b.
mm, m, cm, km.
d.
km, m, cm, mm.
 

 17. 
Which of these metric units is used to measure mass?
a.
m
c.
g
b.
mm
d.
L
 

 18. 
The quantity of matter per unit volume is
a.
mass.
c.
inertia.
b.
weight.
d.
density.
 

 19. 
The unit m3 measures
a.
length.
c.
volume.
b.
area.
d.
time.
 

 20. 
The liter is defined as
a.
1000 m3.
c.
1000 g3.
b.
1000 cm3.
d.
1000 c3.
 

 21. 
The standard base unit for mass is the
a.
gram.
c.
meter.
b.
cubic centimeter.
d.
kilogram.
 

 22. 
A volume of 1 milliliter is equivalent to
a.
1 cubic centimeter.
c.
1 liter.
b.
1 gram.
d.
10–1 cubic decimeters.
 

 23. 
Which of these symbols represents a unit of volume?
a.
mL
c.
mm
b.
mg
d.
cm
 

 24. 
The SI base unit for time is the
a.
day.
c.
minute.
b.
hour.
d.
second.
 

 25. 
Which of these is the abbreviation for the SI base unit of time?
a.
hr
c.
sec
b.
h
d.
s
 

 26. 
The most appropriate SI unit for measuring the length of an automobile is the
a.
millimeter.
c.
meter.
b.
kilometer.
d.
liter.
 

 27. 
The SI base unit for length is the
a.
meter.
c.
centimeter.
b.
millimeter.
d.
kilometer.
 

 28. 
All of the following are SI units for density except
a.
kg/m3.
c.
g/cm3.
b.
kg/L.
d.
g/m2.
 

 29. 
A change in the force of gravity on an object will affect its
a.
mass.
c.
weight.
b.
density.
d.
kinetic energy.
 

 30. 
Which of these is a measure of Earth's gravitational pull on matter?
a.
density
c.
volume
b.
weight
d.
mass
 

 31. 
Which of these is a measure of the amount of material?
a.
density
c.
volume
b.
weight
d.
mass
 

 32. 
Which of these statements about mass is true?
a.
Mass is expressed in pounds or newtons.
b.
Mass is usually measured with a spring scale.
c.
The mass of an object depends on the force of gravity acting on it.
d.
The mass of an object is determined by comparing it to an object of known mass.
 

 33. 
Which pair of quantities determines the density of a material?
a.
mass and weight
c.
volume and concentration
b.
volume and weight
d.
volume and mass
 

 34. 
The relationship between the mass m of a material, its volume V, and its density D is
a.
D = mV.
c.
D = m/V.
b.
D = V/m.
d.
D = m + v.
 

 35. 
The density of an object is calculated by
a.
multiplying its mass times its volume.
b.
dividing its mass by its volume.
c.
dividing its volume by its mass.
d.
adding its mass to its volume.
 

 36. 
When density is measured,
a.
a graduated cylinder is always used.
b.
the units are always kg/m3.
c.
the temperature should be specified.
d.
the material must be a pure substance.
 

 37. 
Which of these statements about density is true?
a.
Larger objects are more dense.
b.
Density does not depend on temperature.
c.
Density is a physical property.
d.
The density of an object depends on the force of gravity.
 

 38. 
The density of aluminum is 2.70 g/cm3. What is the mass of a solid piece of aluminum with a volume of 1.50 cm3?
a.
0.556 g
c.
4.05 g
b.
1.80 g
d.
4.20 g
 

 39. 
A sample of gold has a mass of 96.5 g and a volume of 5.00 cm3. The density of gold is
a.
0.0518 g/cm3.
c.
101.5 g/cm3.
b.
19.3 g/cm3.
d.
483 g/cm3.
 

 40. 
The density of pure diamond is 3.5 g/cm3. What is the volume of a diamond with a mass of 0.25 g?
a.
0.071 cm3
c.
3.75 cm3
b.
0.875 cm3
d.
14 cm3
 

 41. 
What is the density of 37.72 g of material whose volume is 6.80 cm3?
a.
0.180 g/cm3
c.
30.9 g/cm3
b.
5.55 g/cm3
d.
256. g/cm3
 

 42. 
100 milliliters is equivalent to
a.
1 hectoliter.
c.
1 centiliter.
b.
1 microliter.
d.
1 deciliter.
 

 43. 
0.25 g is equivalent to
a.
250 kg.
c.
0.025 mg.
b.
250 mg.
d.
0.025 kg.
 

 44. 
0.05 cm is the same as
a.
0.000 05 m.
c.
0.05 m.
b.
0.005 mm.
d.
0.5 mm.
 

 45. 
1.06 L of water is equivalent to
a.
0.001 06 mL.
c.
106 mL.
b.
10.6 mL.
d.
1060 mL.
 

 46. 
The number of grams equal to 0.5 kg is
a.
0.0005.
c.
500.
b.
0.005.
d.
5000.
 

 47. 
How many minutes are in 1 week?
a.
168 min
c.
10 080 min
b.
1440 min
d.
100 800 min
 

 48. 
If 1 inch equals 2.54 cm, how many centimeters equal 1 yard?
a.
0.0706 cm
c.
30.5 cm
b.
14.2 cm
d.
91.4 cm
 

 49. 
A measurement that closely agrees with an accepted value is best described as
a.
precise.
c.
significant.
b.
reproducible.
d.
accurate.
 

 50. 
A numerical result is said to have good precision if
a.
it agrees closely with an accepted value.
b.
repeated measurements agree closely.
c.
it has a small number of significant figures.
d.
it is a large whole number.
 

 51. 
If repeated measurements agree closely but differ widely from the accepted value, these measurements are
a.
neither precise nor accurate.
b.
accurate, but not precise.
c.
both precise and accurate.
d.
precise, but not accurate.
 

 52. 
These values were recorded as the mass of products when a chemical reaction was carried out three separate times: 8.83 g; 8.84 g; 8.82 g. The mass of products from that reaction is
8.60 g. The values are
a.
accurate, but not precise.
b.
precise, but not accurate.
c.
both accurate and precise.
d.
neither accurate nor precise.
 

 53. 
A chemist obtained the values 5.2246 g, 5.2353 g, and 5.2501 g for the mass of a sample. Without knowing the true mass of the sample, it can be said that these values have
a.
good precision.
b.
good accuracy.
c.
poor precision.
d.
poor accuracy.
 

 54. 
For numbers less than 0.1, such as 0.06, the zeros to the right of the decimal point but before the first nonzero digit
a.
are significant.
b.
show the decimal place of the first digit.
c.
show that the zero on the left side of the decimal is not significant.
d.
show uncertainty.
 

 55. 
The measurement 0.035550 g rounded off to two significant figures would be
a.
0.03 g.
c.
0.036 g.
b.
0.35 g.
d.
3.5 ´ 102 g.
 

 56. 
When adding numbers, the sum should be rounded so that the final digit is in the same place as the
a.
rightmost digit of the numbers added.
b.
last digit in the longest number added.
c.
leftmost digit of the numbers added.
d.
leftmost digit of the shortest number added.
 

 57. 
The number of significant figures in the measurement 0.000 305 kg is
a.
2.
c.
6.
b.
3.
d.
7.
 

 58. 
The number of significant figures in the measured value 0.032 0 g is
a.
2.
c.
4.
b.
3.
d.
5.
 

 59. 
Which of these measurements has been expressed to three significant figures?
a.
0.052 g
c.
3.065 g
b.
0.202 g
d.
500 g
 

 60. 
Which of these measurements has been expressed to four significant figures?
a.
0.0020 mm
c.
30.00 mm
b.
0.0402 mm
d.
402.10 mm
 

 61. 
The number of significant figures in the measurement 2010 cm is
a.
1.
c.
3.
b.
2.
d.
4.
 

 62. 
Which of these measurements has only nonsignificant zeros?
a.
0.0037 mL
c.
400. mL
b.
60.0 mL
d.
506 mL
 

 63. 
Using a metric ruler with 1 mm divisions, the sides of a rectangular piece of plywood were measured as 3.54 cm and 4.85 cm, which corresponds to an area of 17.1690 cm2. Which of these shows the area expressed correctly?
a.
17.1 cm2.
c.
17.17 cm2.
b.
17.169 cm2.
d.
17.2 cm2.
 

 64. 
When 64.4 is divided by 2.00, the correct number of significant figures in the result is
a.
1.
c.
4.
b.
3.
d.
6.
 

 65. 
The dimensions of a rectangular solid are measured to be 1.27 cm, 1.3 cm, and 2.5 cm. The volume should be recorded as
a.
4.128 cm3.
c.
4.13 cm3.
b.
4.12 cm3.
d.
4.1 cm3.
 

 66. 
Three samples of 1.12 g, 1.8 g, and 1.562 g are mixed together. The combined mass of the three samples, expressed to the correct number of significant figures, would be recorded as
a.
4.4 g.
c.
4.482 g.
b.
4.48 g.
d.
4.5 g.
 

 67. 
When 5.7 m is divided by 2 s, the quotient is correctly reported as
a.
2.8 m/s.
c.
2.9 m/s.
b.
2.85 m/s.
d.
3 m/s.
 

 68. 
The product of 13 cm and 5.7 cm is correctly reported as
a.
74 cm2.
c.
74.1 cm2.
b.
74.0 cm2.
d.
75 cm2.
 

 69. 
What is 1.245 633 501 ´ 108 rounded to four significant figures?
a.
1246
c.
1.246 ´ 108
b.
1.2456 ´ 108
d.
1.246 ´ 104
 

 70. 
How many significant figures would the answer to the following calculation have?

3.475 ´ 1.97 + 2.4712 is
a.
2
c.
4
b.
3
d.
5
 

 71. 
How many significant digits should be shown in the product of 1.6 cm and 2.4 cm?
a.
1
c.
3
b.
2
d.
4
 

 72. 
How is the measurement 0.000 065 cm written in scientific notation?
a.
65 ´ 10–6 cm
c.
6.5 ´ 10–6 cm
b.
6.5 ´ 10–5 cm
d.
6.5 ´ 10–4 cm
 

 73. 
The measurement 0.020 L is the same as
a.
2.0 ´ 10–3 L.
c.
2.0 ´ 10–2 L.
b.
2.0 ´ 102 L.
d.
2.0 ´ 10–1 L.
 

 74. 
How would 0.00930 m be expressed in scientific notation?
a.
93 ´ 10–4 m
c.
9.30 ´ 10–3 m
b.
9.3 ´ 10–4 m
d.
9.30 ´ 10–5 m
 

 75. 
The speed of light is 300 000 km/s. In scientific notation, this speed is written to one significant figure as
a.
3 ´ 105 km/s.
c.
3. ´ 106 km/s.
b.
3.0 ´ 105 km/s.
d.
3.0 ´ 106 km/s.
 

 76. 
The average distance between the Earth and the moon is 386 000 km. Expressed in scientific notation, this distance is written as
a.
386 ´ 103 km.
c.
3.9 ´ 105 km.
b.
39 ´ 104 km.
d.
3.86 ´ 105 km.
 

 77. 
An analytical balance can measure mass to the nearest 0.0001 g. In scientific notation, the accuracy of the balance would be expressed as
a.
1.0 ´ 10–3 g.
c.
1 ´ 104 g.
b.
1 ´ 103 g.
d.
1 ´ 10–4 g.
 

 78. 
When 1.92 ´ 10–6 kg is divided by 6.8 ´ 102 mL, the quotient equals
a.
2.8 ´ 10–4 kg/mL.
c.
2.8 ´ 10–8 kg/mL.
b.
2.8 ´ 10–5 kg/mL.
d.
2.8 ´ 10–9 kg/mL.
 

 79. 
When 6.02 ´ 1023 is multiplied by 9.1 ´ 10–31, the product is
a.
4.3 ´ 10–8.
c.
4.3 ´ 10–7.
b.
4.3 ´ 1054.
d.
4.3 ´ 10–53.
 

 80. 
The result of dividing 107 by 10–3 is
a.
10–4.
c.
104.
b.
102.5.
d.
1010.
 

 81. 
The capacity of a Florence flask is 250 mL. Its capacity in liters expressed in scientific notation is
a.
2.5 ´ 10–2 L.
c.
2.5 ´ 101 L.
b.
2.5 ´ 10–1 L.
d.
2.5 ´ 102 L.
 

 82. 
If values for x and y vary as an inverse proportion,
a.
their quotient is a constant.
c.
their product is a constant.
b.
their graph is a parabola.
d.
their graph is a straight line.
 

 83. 
Two variables are directly proportional if their ____ has a constant value.
a.
sum
c.
quotient
b.
difference
d.
product
 

 84. 
The graph of two variables that are directly proportional to one another is
a.
a straight line.
c.
a parabola.
b.
an ellipse.
d.
a hyperbola.
 

 85. 
Two variables are inversely proportional if their ____ has a constant value.
a.
sum
c.
product
b.
difference
d.
quotient
 

 86. 
The graphs of two variables that are inversely proportional to one another is
a.
a straight line.
c.
a parabola.
b.
an ellipse.
d.
a hyperbola.
 

 87. 
Which of these statements about y = kx is not true?
a.
y is directly proportional to x.
b.
x is a variable.
c.
The product of y and x is a constant.
d.
The graph of y versus x is be a straight line.
 

 88. 
Which of these equations does not describe an inverse proportionality between x and y?
a.
xy = k
c.
y = k/x
b.
x = k/y
d.
k = x/y
 

 89. 
Which of the following does not describe a direct proportionality between x and y?
a.
xy = k
c.
y/x = k
b.
x/y = k
d.
x = ky
 

 90. 
In the equation density = mass/volume, mass divided by volume has a constant value. This means that the
a.
equation graphs as a straight line.
b.
variables mass and volume are inversely proportional.
c.
equation graphs as a hyperbola.
d.
product of mass and volume is a constant.
 

Short Answer
 

 91. 
Explain the differences between qualitative and quantitative observations.
 

 92. 
Define the terms theory and hypothesis in a way that shows the role of each in the scientific method.
 

 93. 
The model of a water molecule below is made with toothpicks and plastic balls.

sa093-1.jpg

Describe one way in which this model is like a water molecule and one way it is different from a water molecule.
 

 94. 
What is the most appropriate SI unit for expressing the mass of a dog?
 

 95. 
Show how SI units for volume and density are derived from SI base units for length and mass.
 

 96. 
Identify two prefixes that can be added to an SI base unit to change its magnitude. For each prefix, tell how the magnitude changes (e.g., 10 times greater, 1000 times smaller, etc.).
 

 97. 
Distinguish between mass and weight.
 

 98. 
Distinguish between precision and accuracy.
 

Essay
 

 99. 
Using the two models shown below explain how each model resembles the object it represents. Explain how each model differs from the object it represents.

es099-1.jpg
 

 100. 
The table below show measurements made on samples of three unknown materials. Explain how this data could be used to identify the three materials.

Mass and Volume Data
Material
Mass (g)
Volume (mL)
1
6.02
2.23
2
18.42
2.34
3
35.15
3.10
 



 
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