2020 Chemistry Olympiad online Class 1st Year/Huang
Chapter 1 - Chemical Foundations
1. List the fundamental units that you would combine to get the following derived units (you may need to
look up the meaning of some of the terms):
a. velocity
b. acceleration
c. volume
d. specific heat
e. density
f. pressure
2. Put the following prefixes in order from smallest to largest: femto, tera, mega, deci, kilo, atto, exa.
3. Put the following prefixes in order from largest to smallest: giga, hecto, micro, peta, milli, nano, pico.
4. What SI prefixes correspond to the following multipliers?
a. 103
b. 10-6
c. 109
d. 10-12
e. 10-2
5. Bottles of wine sometimes carry the notation “Volume = 75 cL.” What does the unit cL mean?
6. What do the following abbreviations stand for?
a. dL
b. dm
c. µm
d. nL
e. MJ
7. What units do the following abbreviations represent?
a. µg
b. dm
c. ps
d. kA
e. mmol
8. Which quantity in each of the following pairs is larger?
a. 5.63 x 106 cm or 6.02 x 101 km
b. 46 µs or 3.2 x 10-2 ms
c. 200,098 g or 17 x 101 kg
9. How many picograms are in 1 mg? In 35 ng?
10. How many microliters are in 1 L? In 20 mL?
11. Carry out the following conversions:
a. 5 pm = _______ cm = _______ nm
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2020 Chemistry Olympiad online Class 1st Year/Huang
b. 8.5 cm3 = ________ m3 = _______ mm3
c. 65.2 mg = ________ g = _______ pg
12. Concentrations of substances dissolved in solution are often expressed as mass per unit volume. For
example, normal human blood has a cholesterol concentration of about 200 mg/100 mL. Express this
concentration in the following units:
a. mg/L
b. µg/mL
c. g/L
d. ng/µL.
13. Perform each of the following conversions.
a. 8.43 cm to millimeters
b. 2.41 x 102 cm to meters
c. 294.5 nm to centimeters
d. 1.445 x 104 m to kilometers
e. 235.3 m to millimeters
f. 903.3 nm to micrometers.
14. How many significant figures are in each of the following measurements?
a. 35.0445 g
b. 59.0001 cm
c. 0.03003 kg
e. 67,000 m3
f. 3.8200 x 103 L
d. 0.00450 m
15. How many significant figures are in each of the following measurements?
a. $130.95
b. 2000.003 g
e. 5.10 x 102 J
d. 510 J
f. 10 students
16. How many significant figures are in each of the following measurements?
a. 6.07 x 10-15
b. 0.003840
c. 17.00
d. 8 x 108
e. 463.8052
17. How many significant figures are in each of the following measurements?
a. 1406.20
b. 0.0007
c. 1600.0
d. 0.0261140
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2020 Chemistry Olympiad online Class 1st Year/Huang
18. Which value has more significant figures?
7.63 x 10-11 or 0.00076
19. Use exponential notation to express the number 37,100,000 with:
a. one significant figures
b. two significant figures
c. 3 significant figures
d. 5 significant figures
e. 6 significant figures
f. 7 significant figures
20. Perform the indicated calculations on the following measured values, giving the final answer with the
correct number of significant figures.
a. 16.81 + 3.2257
b. 324.6 + 815.991
c. (3.8 x 10-12 + 4 x 10-13)/(4 x 1012 + 6.3 x 1013)
d. 3.14159 x 68/(5.18 x 10-11 – 6 x 10-4)
21. Perform the indicated calculations on the following measured values, giving the final answer with the
correct number of significant figures.
a. 2.85 + 3.4621 + 1.3
b. 7.442 – 7.429
c. 1.65 x 14
d. 27/4.148
e. [(3.901 – 3.887)/3.901] x 100.0
f. 6.404 x 2.91 x (18.7 – 17.1)
22. Express the results of the following calculations with the correct number of significant figures:
a. 4.884 X 2.05
b. 94.61 ÷ 3.7
c. 3.7 ÷ 94.61
d. 86.3 + 1.42 - 0.09
e. 5502.3 + 24 + 0.01
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2020 Chemistry Olympiad online Class 1st Year/Huang
f. 5.7 X 2.31
23. Define the following terms:
a. accuracy
b. precision
c. random error
d. systematic error
24. Which of the following is the estimated error for 12.3008 g of sugar?
a. +/- 0.001
b. +/- 0.0001
c. +/- 0.0008
d. +/- 0.00001
25. Which number has the greatest uncertainty?
a. 1.02 +/- 0.01
b. 4.60 +/- 0.01
c. 100.0 +/- 10.00
d. 1.00 +/- 0
26. Round 20.589958 to 4, 3, and 2 significant figures, respectively.
27. The solution to (22.41 + 0.464) x 999/18.465.
28. The solution to 9.99/[22.41 x (18.465 + 0.464)].
29. When an irregularly shaped chunk of silica weighing 8.763 g was placed in a graduated cylinder
containing 25.00 mL of water, the water level in the cylinder rose to 28.76 mL. What is the density of
silicon in g/mL?
30. Characterize each of the following dartboards according to the accuracy and precision of the
results.
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2020 Chemistry Olympiad online Class 1st Year/Huang
31. How many milliliters of water does the graduated cylinder in (a) container? (b) How many
significant figures do you have in each answer?
32. Three students weighed the same sample of copper shot five times. Their results were as follows:
Weighing
1
2
3
4
5
student #1
17.516 g
17.888 g
19.107 g
21.456 g
19.983 g
student #2
15.414 g
16.413 g
14.408 g
15.637 g
15.210 g
student #3
13.893 g
13.726 g
13.994 g
13.810 g
13.476 g
a. Calculate the mean (average) mass of the sample determined by each student.
b. If the true mass of copper shot is 15.384 g, which student was most accurate? Which was most precise?
What could be the possible sources of error in the determinations?
33. Which is larger, a Fahrenheit degree or a Celsius degree? By how much?
34. What is the difference between a kelvin and a Celsius degree?
35. The normal body temperature of a goat is 39.9 °C, and that of an Australian spiny anteater is
22.2 °C. Express these temperatures in degrees Fahrenheit.
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2020 Chemistry Olympiad online Class 1st Year/Huang
36. Of that 90 or so naturally occurring elements, only four are liquid near room temperature:
mercury (melting point = -38.87 °C), bromine (melting point =. -7.2 °C), cesium (melting point
= 28.40 °C), and gallium (melting point = 29.78 °C). Convert these melting points to degrees
Fahrenheit.
37. Tungsten, the element used to make filaments in light- bulbs, has a melting point of 6192 °F.
Convert this t e m p e r a t u r e to degrees Celsius and to kelvin.
38. Suppose you were dissatisfied w i t h both Celsius and Fahrenheit units and wanted to design
your own temperature scale based on ethyl alcohol (ethanol). On the Celsius scale, ethanol has a
melting point of -117.3 °C and a boiling point of 78.5 °C, but on your new scale calibrated in units
0
of degrees ethanol, E, you define ethyl alcohol to melt at 0 °E and boil at 200 °E.
a. How does your ethyl alcohol degree compare in size with a Celsius degree?
b. How does an ethanol degree compare in size with a Fahrenheit degree?
c. What are the melting and boiling points of water on the ethanol scale?
d. What is normal human body temperature (98.6 °F) on the etl1anol scale?
e. If the outside thermometer reads 130 °E, how would you dress to go out?
39. A column of liquid is found to expand linearly on heating 5.25 cm for a 10.0 °F rise in temperature.
If the initial temperature of the liquid is 98.6°F, what will the final temperature be in °C if the liquid
has expanded by 18.5 cm?
40. In each of the following pairs, which has the greater mass?
a. 1.0 kg of feathers or 1.0 kg of lead
b. 1.0 mL of mercury or 1.0 mL of water
c. 19.3 mL of water or 1.00 mL of gold
d. 75 mL of copper or 1.0 L of benzene
41. In each of the following pairs, which has the greater volume?
a. 1.0 kg of feathers or 1.0 kg of lead
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2020 Chemistry Olympiad online Class 1st Year/Huang
b. 1 00 g of gold or 100 g of water
c. 1.0 L of copper or 1.0 L of mercury
42. The density of silver is 10.5 g/cm3. What is the mass (in kilograms) of a cube of silver that
measures 0.62 m on each side?
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43. A vessel contains 4.67 L of bromine, whose density is 3.10 g/cm . What is the mass of the
bromine in the vessel (in kilograms)?
44. Aspirin has a density of 1.40 g/cm3. What is the volume in cubic centimeters of an aspirin tablet
weighing 250 mg? Of a tablet weighing 500 lb?
45. Gaseous hydrogen has a density of 0.0899 g/L at 0°C, and gaseous c h l o r i n e has a density
of 3.214 g/L at the same temperature. How many liters of each would you need if you wanted
1.0078 g of hydrogen and 35.45 g of chlorine?
46. What is the density of lead in g/cm3 if a rectangular bar measuring 0 . 5 0 cm in height,
1.55 cm in width, and 25.00 cm in length has a mass of 220.9 g?
47. What is the density of lithium metal in g/cm3 if a cylindrical wire with a diameter of 2.40 mm
and a length of 15.0 cm has a mass of 0.3624 g?
48. Define the following terms: solid, liquid, gas, pure substance, element, compound,
homogeneous mixture, heterogeneous mixture, solution, chemical change, physical change.
49. What is the difference between homogeneous and heterogeneous matter? Classify each
of the following as homogeneous or heterogeneous.
a. a door
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2020 Chemistry Olympiad online Class 1st Year/Huang
b. the air you breathe
c. a cup of coffee (black)
d. the water you drink
e. salsa
f. your lab partner
50. Classify each of the following as a mixture or a pure substance.
a. water
f. uranium
b. blood
g. wine
c. the oceans
h. leather
d. iron
i. table salt (NaCl )
e. brass
Of the pure substances, which are elements and which are compounds?
51. Classify the following physical or chemical changes.
a. Moth balls gradually vaporize in a closet.
b. Hydrofluoric acid attacks glass, and is used to etch calibration marks on glass laboratory utensils.
c. A French chef making a sauce with brandy is able to burn off the alcohol from the brandy, leaving just
the brandy flavoring.
d. Chemistry majors sometimes get holes in the cotton jeans they wear to lab because of acid spills.
52. The properties of a mixture are typically averages of the properties of its components. The properties
of a compound may differ dramatically from the properties of the elements that combine to produce the
compound. For each process described below, state whether the material being discussed is most likely a
mixture or a compound, and state whether the process is a chemical change or a physical change.
a. An orange liquid is distilled, resulting in the collection of a yellow liquid and a red solid.
b. A colorless, crystalline solid is decomposed, yielding a pale yellow-green gas and a soft, shiny metal.
c. A cup of tea becomes sweeter as sugar is added to it.
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2020 Chemistry Olympiad online Class 1st Year/Huang
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