AT Chemistry
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Chapter 1 Review Problems
1. You have two beakers, one filled to the 100-mL mark with sugar *the sugar has a mass of 180.0
g) and the other filled to the 100-mL mark with water (the water has a mass of 100.0 g). You
pour all of the sugar and all of the water together in a big beaker and stir until the sugar is
completely dissolved.
a)
Which of the following is true about the mass of the solution? Explain.
i.
ii.
iii.
iv.
v.
It is much greater than 280.0 g
It is somewhat greater than 280.0 g
It is exactly 280.0 g
It is somewhat less than 280.0 g
It is much less than 280.0 g
b) Which of the following is true about the volume of the solution? Explain.
i.
ii.
iii.
iv.
v.
2.
it is much greater than 200.0 mL
It is somewhat greater than 200.0 mL
It is exactly 200.0 mL
It is somewhat less than 200.0 mL
It is much less than 200.0 mL
You may have noticed that when water boils, you can see bubbles that rise to the surface of the
water.
a)
What is inside these bubbles?
i.
ii.
iii.
iv.
v.
Air
Hydrogen and oxygen gas
Oxygen gas
Water vapor
Carbon dioxide gas
b) Is the boiling of water a chemical or physical change? Explain.
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3. Sketch two pieces of glassware: one that can measure volume to the thousandth place and one
that can measure volume only to the ones place. Which is more precise?
4. How many significant figures are there in each of the following values?
a) 6.07 X 10-15
b) 0.003840
c) 17.00
d) 8 X 108
e) 463.8052
f)
300
g) 301
h) 300.
5. Evaluate each of the following and write the answer to the appropriate number of significant
figures.
a)
212.2 + 26.7 + 402.09
b) 1.0028 + 0.221 + 0.10337
c) 52.331 + 26.01 -0.9981
d) 2.01 X 102 + 3.014 X 103
e) 7.255 – 6.8350
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6. Perform the following mathematical operations and express the result to the correct number of
significant figures.
a)
b)
2.526
3.1
+
0.470
0.623
+
80.705
0.4326
(6.404 𝑋 2.91)
(18.7−17.1)
c) 6.071 X 10-5 – 8.2 X 10-6 – 0.521 X 10-4
d) (3.8 X 10-12 + 4.0 X 10-13)/(4 X 1012 + 6.3 X 1013)
e)
9.5+4.1+2.8+3.175
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(4 is exact)
f) (8.925 -8.905)/8.925 X 100 (100 is exact)
7. Perform the following conversions
a) 8.43 cm to millimeters
b) 294.5 nm to centimeters
c) 1.445 X 104 m to kilometers
d) 903.3 nm to micrometers
8. Science fiction often uses nautical analogies to describe space travel. If the starship U.S.S.
Enterprise is traveling at warp factor 1.71, what is its speed in knots and in miles per hour?
(Warp 1.71 = 5.00 times the speed of light; speed of light = 3.00X 108 m/s; 1 knot = 2000 yd/hr,
exactly).
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9. A star estimated to have a mass of 2.0 X 1036 kg. Assuming it to be a sphere of average radius
7.0 X 105 km, calculate the average density of the star in units of grams per cubic centimeter.
10. The density of osmium (the densest metal) is 22.57 g/cm3. If a 1.00 kg rectangular block of
osmium has two dimensions of 4.00 cm X 4.00 cm, calculate the third dimension of the block.
11. Classify each of the following as a mixture or a pure substance.
a)
b)
c)
d)
e)
f)
g)
h)
i)
Water
Blood
The oceans
Iron
Brass
Uranium
Wine
Leather
Table salt
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12. Which of the following are chemical changes? Which are physical changes?
a)
b)
c)
d)
e)
f)
The cutting of food
Interaction of food with saliva and digestive enzymes
Proteins being broken down into amino acids
Complex sugars being broken down into simple sugars
Making maple syrup by heating maple sap to remopve water through evaporation
DNA unwinding
13. In recent years, there has been a large push for an increase in renewable resources to prodiuce
the energy we need to power our vehicles. One of the newer fuels that has become more
widely available is a mixture of 85% ethanol and 15% gasoline, E85. Despite being more
environmentally friendly, one of the potential drawbacks of E85 fuel is that it produces less
energy than conventional gasoline. Assume a car gets 28.0 mi/gal using gasoline at $3.50/gal
and 22.5 mi/gal using E85 at $2.85/gal. How much will it cost to drive 500. miles using each
fuel?
14. A laboratory instructor gives a sample of amino acid powder to each of four students, I, II, II, and
IV, and they weigh the samples. The true value is 8.72 g. The results for three trials are:
I.
8.72g, 8.74 g, 8.70 g
II.
8.65 g, 8.77 g, 8.83 g
III.
8.50 g, 8.48 g, 8.51 g
IV.
8.41 g, 8.72 g, 8.55 g
a) Calculate the average mass from each set of data, and indicate which set is the most
accurate.
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b) Precision is a measure of the average of the deviations of each piece of data from the
average value. Which set of data is the most precise? Is this set also the most accurate?
c) Which set of data is the least accurate? Which is the least precise?
d) Is there any set(s) of data that would indicate systematic error? Explain.
15. A student obtained the following data for a piece of metal:
Mass
Volume
a)
6.72 g + 0.01g
2.35 mL + 0.05 mL
Calculate the density of the metal and include the uncertainty.
b) The density of aluminum is 2.70 g/mL. Could the student’s sample be aluminum metal?
Explain.
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c) Identify two other properties that could be used to distinguish the sample from other
metals.
16. AT chemistry students at SHS performed an experiment to determine the melting point of a
solid based on its heating-cooling curve. The following data were obtained:
trial
melting point (oC)
1
2
3
4
5
6
7
49.0
47.4
46.8
50.3
48.1
53.8
49.4
a) Determine the average.
b) Calculate the standard deviation.
c) Are all measurements statistically valid? Explain.
17. A television advertisement from the “National Collector’s Mint” implores you to “own a piece of
history” by purchasing a 2010 $50 Gold Buffalo Tribute Proof. This special commemorative
release is the purest gold coin ever made by the U.S. government. It’s the first U.S. coin ever
struck using 0.9999 pure 24KT Gold. Each 2010 $50 Gold Buffalo Tribute Proof comes complete
with an individually numbered Certificate of Authenticity, verifying that each piece is clad in 14
mgs of pure 24KT gold. But now, and only for the next seven days only, you can purchase this
collectible for only $9.95 plus 4.95 S&H. There is a strict limit of 5 per order.
Look up the current price of gold and determine the actual cost of this magnificent
commemorative based on its gold content. As P.T. Barnum said….
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