NAME:
Ch 10 Chemical Quantities
Period:
Study Guide
/75
Matching
Match each item with the correct statement below.
a. molar volume
b. molar mass
c. atomic mass
____
____
____
1. the number of grams of an element that is numerically equal to the atomic mass of the element in amu
2. the mass of a mole of any element or compound
3. the volume occupied by a mole of any gas at STP
Match each item with the correct statement below.
a. representative particle
d. percent composition
b. mole
e. standard temperature and pressure
c. Avogadro's number
f. empirical formula
____
____
____
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____
____
4.
5.
6.
7.
8.
9.
the number of representative particles of a substance present in 1 mole of that substance
an atom, an ion, or a molecule, depending upon the way a substance commonly exists
the SI unit used to measure amount of substance
0 C and 1 atm
the percent by mass of each element in a compound
the smallest whole number ratio of the atoms in a compound
Multiple Choice
Identify the choice that best completes the statement or answers the question.
____
____
____
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____
____
1. What SI unit is used to measure the number of representative particles in a substance?
a. kilogram
b. ampere
c. kelvin
d. mole
2. How many hydrogen atoms are in 5 molecules of isopropyl alcohol, C H O?
a. 5
c. 35
(6.02
10 )
b. 5
d. 35
(6.02
10 )
3. If a dozen Clementine oranges have a mass of 744 g, what will be the mass of 15 Clementines?
a. 11.16 kg
b. 595 g
c. 896 g
d. 930 g
4. Which of the following elements exists as a diatomic molecule?
a. neon
b. lithium
c. nitrogen
d. sulfur
5. Avogadro's number of representative particles is equal to one ____.
a. kilogram
b. gram
c. kelvin
d. mole
6. Which of the following is equal to Avogadro's number?
a. the number of atoms of bromine in 1 mol Br
b. the number of molecules of chlorine in 0.50 mol Cl
c. the number of molecules of nitrogen in 1 mol N
d. the number of atoms in 1 mol CO
____
____
7. How many moles of tungsten atoms are in 4.8
10 atoms of tungsten?
a. 8.0
c. 1.3
10 moles
10 moles
b. 8.0
d. 1.3
10 moles
10 moles
8. How many moles of silver atoms are in 1.8
10
a. 3.0
b.
c.
10
3.3
10
____ 9. How many atoms are in 0.075 mol of titanium?
a. 1.2
10-25
b. 2.2
c.
10
____ 10. How many molecules are in 2.10 mol CO ?
a. 2.53
c.
10 molecules
b. 3.79
d.
10 molecules
atoms of silver?
3.0
10
d. 1.1
10
6.4
d. 4.5
10
3.49
1.26
____ 11. How many atoms are in 3.5 moles of arsenic atoms?
a. 5.8
c. 2.1
10
atoms
b. 7.5
d. 1.7
10 atoms
10
10
10
10
10
molecules
molecules
atoms
atoms
____ 12. Butanol is composed of carbon, hydrogen, and oxygen. If 1.0 mol of butanol contains 6.0
10
hydrogen, what is the subscript for the hydrogen atom in the molecular formula for butanol?
a. 1
b. 10
c. 6
d. 8
____ 13. The atomic masses of any two elements contain the same number of ____.
a. atoms
b. grams
c. ions
d. milliliters
atoms of
Use the following information to answer the next question:
An average bushel of apples has a mass of 10 kg and contains 5 dozen apples.
____ 14. What would be the average mass of 6 apples?
a. 1.0 kg
b. 4.0 kg
c. 0.50 kg
d. 2.0 kg
____ 15. What is true about the molar mass of chlorine gas?
a. The molar mass is 35.5 g.
b. The molar mass is 71.0 g.
c. The molar mass is equal to the mass of one mole of chlorine atoms.
d. none of the above
____ 16. The mass of a mole of NaCl is the
a. molar mass.
b. atomic mass.
c. molecular mass. d. compound mass.
____ 17. What is the molar mass of AuCl3?
a. 96 g
b. 130 g
c. 232.5 g
d. 303.6 g
____ 18. What is the molar mass of (NH ) CO ?
a. 144 g
b. 138 g
c. 96 g
d. 78 g
____ 19. The molar mass of C H and the molar mass of CaCO contain approximately the same number of ____.
a. carbon atoms
b. anions
c. cations
d. grams
____ 20. What is the mass in grams of 5.90 mol C H ?
a. 0.0512 g
b. 19.4 g
c. 389 g
d. 673 g
____ 21. What is the number of moles in 432 g Ba(NO ) ?
a. 0.237 mol
b. 0.605 mol
c. 1.65 mol
d. 3.66 mol
____ 22. What is the number of moles of beryllium atoms in 36 g of Be?
a. 0.25 mol
b. 4.0 mol
c. 45.0 mol
d. 320 mol
____ 23. How many moles of CaBr are in 5.0 grams of CaBr ?
a. 2.5
d. 1.0
10 mol b. 4.2
10 mol c. 4.0
10 mol
10 mol
____ 24. For which of the following conversions does the value of the conversion factor depend upon the formula of
the substance?
a. volume of gas (STP) to moles
c. mass of any substance to moles
b. density of gas (STP) to molar mass
d. moles of any substance to # of particles
____ 25. What is the mass of silver in 3.4 g AgNO ?
a. 0.025 g
b. 0.64 g
c. 2.2 g
d. 3.0 g
____ 26. What is the mass of oxygen in 250 g of sulfuric acid, H SO ?
a. 0.65 g
b. 3.9 g
c. 16 g
d. 160 g
____ 27. The volume of one mole of a substance is 22.4 L at STP for all ____.
a. gases
b. liquids
c. solids
d. compounds
____ 28. The molar volume of a gas at STP occupies ____.
a. 22.4 L
b. 0 C
c. 1 kilopascal
d. 12 grams
____ 29. Which combination of temperature and pressure correctly describes standard temperature and pressure,
STP?
a. 0 C & 101.3 kPa b. 1 C & 0 kPa
c. 0 C & 22.4 kPa
d. 100 C & 100 kPa
____ 30. The molar mass of a substance can be calculated from its density alone, if that substance is a(n) ____.
a. element
b. gas at STP
c. liquid
d. solid
____ 31. The molar mass of a gas can be determined from which of the following?
a. the density of the gas at STP
c. Avogadro's number
b. the volume of a mole of the gas
d. the volume of a the gas at STP
____ 32. What is the volume, in liters, of 0.500 mol of C H gas at STP?
a. 0.0335 L
b. 11.2 L
c. 16.8 L
d. 22.4 L
____ 33. What is the number of moles in 500 L of He gas at STP?
a. 0.05 mol
b. 0.2 mol
c. 22 mol
d. 90 mol
____ 34. What is the number of moles in 9.63 L of H S gas at STP?
a. 0.104 mol
b. 0.430 mol
c. 3.54 mol
d. 14.7 mol
____ 35. What is the density at STP of the gas sulfur hexafluoride, SF ?
a. 0.153 g/L
b. 6.52 g/L
c. 3270 g/L
d. 3.93
10 g/L
____ 36. The molar mass of a certain gas is 49 g. What is the density of the gas in g/L at STP?
a. 3.6
c. 2.2 g/L
d. 71 g/L
10
g/L b. 0.46 g/L
____ 37. A 22.4-L sample of which of the following substances, at STP, would contain 6.02
10 representative
particles?
a. oxygen
b. gold
c. cesium iodide
d. sulfur
____ 38. If the density of an unknown gas Z is 4.50 g/L at STP, what is the molar mass of gas Z?
a. 0.201 g/mol
b. 5.00 g/mol
c. 26.9 g/mol
d. 101 g/mol
____ 39. Which of the following gas samples would have the largest number of representative particles at STP?
a. 12.0 L He
b. 7.0 L O
c. 0.10 L Xe
d. 0.007 L SO
____ 40. Which of the following gases at STP would have the greatest volume?
a. 4.00 mole of He
c. 0.200 mole of SO
b. 1.00 mole of O
d. 5.00 mole of H
____ 41. If the density of a noble gas is 1.783 g/L at STP, that gas is ____.
a. Kr
b. Xe
c. Ar
d. He
____ 42. To determine the formula of a new substance, one of the first steps is to find the
a. molar mass.
c. volume at STP.
b. percent composition.
d. number of particles per mole.
____ 43. What information is needed to calculate the percent composition of a compound?
a. the weight of the sample to be analyzed and its density
b. the weight of the sample to be analyzed and its molar volume
c. the formula of the compound and the atomic mass of its elements
d. the formula of the compound and its density
____ 44. If 60.2 grams of Hg combines completely with 24.0 grams of Br to form a compound, what is the percent
composition of Hg in the compound?
a. 28.5%
b. 39.9%
c. 71.5%
d. 60.1%
____ 45. What is the percent composition of chromium in BaCrO ?
a. 4.87%
b. 9.47%
c. 20.5%
d. 25.2%
____ 46. If 20.0 grams of Ca combines completely with 16.0 grams of S to form a compound, what is the percent
composition of Ca in the compound?
a. 1.25%
b. 20.0%
c. 44.4%
d. 55.6%
____ 47. What is the percent composition of carbon, in heptane, C H ?
a. 12%
b. 19%
c. 68%
d. 84%
____ 48. What is the percent by mass of carbon in acetone, C H O?
a. 20.7%
b. 62.1%
c. 1.61%
d. 30.0%
____ 49. Which expression represents the percent by mass of nitrogen in NH4NO3?
a. 14 g N/80 g NH NO
c. 80 g NH NO /14 g N
100%
100%
b. 28 g N/80 g NH NO
d. 80 g NH NO /28 g N
100%
100%
____ 50. Which of the following compounds has the lowest percent gold content by weight?
a. AuOH
b. Au(OH)
c. AuCl
d. AuI
____ 51. Which of the following compounds has the highest oxygen content, by weight?
a. Na O
b. CO
c. BaO
d. H O
____ 52. The lowest whole-number ratio of the elements in a compound is called the ____.
a. empirical formula
c. binary formula
b. molecular formula
d. representative formula
____ 53. Which of the following is an empirical formula?
a. C N H
b. C H O
c. Be (Cr O )
d. Sb4S6
____ 54. Which of the following compounds have the same empirical formula?
a. CO & SO
b. C H & C H
c. C H & C H
d. C H
&C H
____ 55. What is the empirical formula of a compound that is 40% sulfur and 60% oxygen by weight?
a. SO
b. SO
c. SO
d. S O
____ 56. What is the empirical formula of a substance that is 53.5% C, 15.5% H, and 31.1% N by weight?
a. C HN
b. C H N
c. C H N
d. CH N
____ 57. The ratio of carbon atoms to hydrogen atoms to oxygen atoms in a molecule of dicyclohexyl maleate is 4 to
6 to 1. What is its molecular formula if its molar mass is 280 g?
a. C H O
b. C H O
c. C H O
d. C H O
____ 58. Which of the following is true about empirical and molecular formulas?
a. The molecular formula of a compound cannot be the same as its empirical formula.
b. The empirical formula of a compound can be some whole-number multiple of its
molecular formula.
c. Several compounds can have the same empirical formula, but have different molecular
formulas.
d. The empirical formula of a compound can be triple its molecular formula.
____ 59. Which of the following sets of empirical formula, molar mass, and molecular formula is correct?
a. CH, 78 g, C H
c. CaO, 56 g, Ca O
b. CH N, 90 g, C H N
d. C H O, 120 g, C H O
Short Answer
1. How many representative particles are in 1.45 g of a molecular compound with a molar mass of 237 g?
2. Find the mass in grams of 3.10
10
molecules of F .
3. Find the number of moles of argon in 607 g of argon.
4. Find the mass, in grams, of 1.40
10
molecules of N .
5. What is the percent composition of NiO, if a sample of NiO with a mass of 41.9 g contains 33.1 g Ni and 8.8 g
O?
6. What is the percent by mass of hydrogen in aspirin, C H O ?
7. Calculate the molecular formulas of the compounds having the following empirical formulas and molar
masses: C H , 58 g/mol; CH, 78 g/mol; and HgCl, 236.1 g/mol.