Deck 5: The Mole and Chemical Formulas

Question 1

A rock contains an element with a molar mass of 40.08 g/mol.If 9.28 × 10²⁴ atoms of this element were found in the rock, how many grams of the unknown element are present in the rock?

A)618 g
B)1.49 × 10²⁸ g
C)2.24 × 10⁵⁰ g
D)0.38 g
E)3.80 g

Answer 1

618 g

Question 2

Calculate the number of moles in 17.8 g of the antacid magnesium hydroxide, Mg(OH)₂.

A)3.28 mol
B)2.32 mol
C)0.431 mol
D)0.305 mol
E)0.200 mol

Answer 2

0.305 mol

Question 3

Five vials each contain 12 grams of a solid metal sample.The samples include calcium, platinum, barium, gold, and silver.Which vial has the fewest moles of metal atoms?

A)Calcium
B)Barium
C)Gold
D)Silver
E)Platinum

Answer 3

Gold

Question 4

What is the molecular mass of acetaminophen, C₈H₉NO₂?

A)43 amu
B)76 amu
C)151 amu
D)162 amu
E)125 amu

Question 5

How many moles are in 8.73 × 10²⁵ atoms of boron, B?

A)145 moles
B)3.84 × 10²⁷ moles
C)1.45 moles
D)5.04 × 10⁻²⁵ moles
E)6.90 × 10⁻³ moles

Question 6

Five vials each contain 12 grams of a solid metal sample.The samples include calcium, platinum, barium, gold, and silver.Which vial has the most metal atoms?

A)Calcium
B)Barium
C)Gold
D)Silver
E)Platinum

Question 7

Calculate the formula mass of (NH₄)₃AsO₄.

A)417.80 amu
B)193.05 amu
C)165.02 amu
D)156.96 amu
E)108.96 amu

Question 8

How many atoms are in 0.534 mol of nickel, Ni?

A)1.13 × 10²⁴ atoms
B)1.48 × 10²⁵ atoms
C)2.44 × 10²² atoms
D)3.22 × 10²³ atoms
E)6.98 × 10²¹ atoms

Question 9

How many grams are present in 0.885 moles of manganese?

A)62.1 g
B)48.6 g
C)21.5 g
D)27.5 g
E)0.016 g

Question 10

Calculate the molar mass of Ca(BO₂)₂·6H₂O.

A)273.87 g/mol
B)233.80 g/mol
C)183.79 g/mol
D)174.89 g/mol
E)143.71 g/mol

Question 11

How many atoms are in 7.12 mol of gold, Au?

A)1.18 × 10⁻²³ atoms
B)4.29 × 10²⁴ atoms
C)8.46 × 10²² atoms
D)4.70 × 10²⁴ atoms
E)3.34 × 10²⁶ atoms

Question 12

How many moles are present in 17.4 g of lead?

A)0.0994 moles
B)1.05 × 10²⁵ moles
C)0.0840 moles
D)10.06 moles
E)11.9 moles

Question 13

Calculate the formula mass of potassium permanganate, KMnO₄.

A)149.91 amu
B)79.41 amu
C)127.41 amu
D)158.04 amu
E)174.04 amu

Question 14

Calcium fluoride, CaF₂, is a source of fluorine and is used to fluoridate drinking water.Calculate its formula mass.

A)118.15 g/mol
B)99.15 g/mol
C)78.08 g/mol
D)59.08 g/mol
E)50.01 g/mol

Question 15

Calculate the molecular mass of tetraphosphorus decaoxide, P₄O₁₀, a corrosive substance which can be used as a drying agent.

A)469.73 amu
B)283.88 amu
C)190.97 amu
D)139.88 amu
E)94.97 amu

Question 16

What is the molar mass of nicotine, C₁₀H₁₄N₂?

A)134 g/mol
B)148 g/mol
C)158 g/mol
D)210 g/mol
E)162 g/mol

Question 17

Determine the mass of hydrogen (in grams) that contains 5.08 × 10¹⁵ hydrogen atoms.

A)5.12 × 10¹⁵ g
B)3.06 × 10³⁹ g
C)3.06 × 10⁻⁹ g
D)8.50 × 10⁻⁹ g
E)8.5 × 10¹⁵ g

Question 18

Calculate the molecular mass of menthol, C₁₀H₂₀O.

A)156 amu
B)140 amu
C)29 amu
D)146 amu
E)136 amu

Question 19

Aluminum sulfate, Al₂(SO₄)₃, is used in tanning leather, purifying water, and the manufacture of antiperspirants.Calculate its molecular or formula mass.

A)450.06 amu
B)342.17 amu
C)315.15 amu
D)278.02 amu
E)74.98 amu

Question 20

Calculate the formula mass of rubidium carbonate, Rb₂CO₃.

A)340.43 amu
B)255.00 amu
C)230.95 amu
D)145.47 amu
E)113.48 amu

Question 21

What is the average mass, in grams, of one atom of iron? (N_A = 6.022 × 10²³ mol⁻¹)

A)6.02 × 10²³ g
B)1.66 × 10⁻²⁴ g
C)9.27 × 10⁻²³ g
D)55.85 g
E)55.85 × 10⁻²³ g

Question 22

What is the mass of 0.0250 mol of P₂O₅?

A)35.5 g
B)5676 g
C)0.0250 g
D)1.51 × 10²² g
E)3.55 g

Question 23

How many moles of aspirin, C₉H₈O₄, are in a tablet that contains 325 mg of aspirin?

A)0.00180 moles
B)0.555 moles
C)0.467 moles
D)0.357 moles
E)2.80 moles

Question 24

Aluminum oxide, Al₂O₃, is used as a filler for paints and varnishes as well as in the manufacture of electrical insulators.Calculate the number of moles in 47.51 g of Al₂O₃.

A)2.377 mol
B)2.146 mol
C)1.105 mol
D)0.4660 mol
E)0.4207 mol

Question 25

What is the mass of one copper atom? (N_A = 6.022 × 10²³ mol⁻¹)

A)1.055 × 10⁻²² g
B)63.55 g
C)1 amu
D)1.66 × 10⁻²⁴ g
E)9.476 × 10²¹ g

Question 26

Sulfur trioxide can react with atmospheric water vapor to form sulfuric acid that falls as acid rain.Calculate the mass in grams of 3.65 × 10²⁰ molecules of sulfur trioxide.

A)6.06 × 10⁻⁴ g
B)2.91 × 10⁻² g
C)4.85 × 10⁻² g
D)20.6 g
E)1650 g

Question 27

How many grams are contained in a 0.183 mol sample of ammonium phosphate?

A)1.23 × 10⁻³ g
B)617 g
C)20.7 g
D)27.3 g
E)815.1 g

Question 28

How many moles of ammonia, NH₃, are in 13.81 g of NH₃?

A)1.234 moles
B)0.8107 moles
C)8.316 × 10²⁴ moles
D)4.881 × 10²³ moles
E)235.3 moles

Question 29

How many moles are present in 17.4 g of lead?

A)0.0994 moles
B)1.05 × 10²⁵ moles
C)0.0840 moles
D)10.06 moles
E)11.9 moles

Question 30

What is the mass of 1.63 × 10²¹ atoms of silicon? (N_A = 6.022 × 10²³ mol⁻¹)

A)2.71× 10⁻²³ g
B)4.58 × 10²² g
C)28.08 g
D)1.04 × 10⁴ g
E)7.60 × 10⁻² g

Question 31

What is the mass of 1.21 × 10²⁰ atoms of sulfur? (N_A = 6.022 × 10²³ mol⁻¹)

A)3.88 × 10²¹ g
B)2.0 mg
C)32.06 g
D)6.44 mg
E)2.00 × 10⁻⁴ g

Question 32

How many grams are contained in a 0.893 mol sample of methane, CH₄?

A)1.48 × 10⁻²⁴ g
B)5.38 × 10²³ g
C)8.64 × 10²⁴ g
D)14.3 g
E)18.0 g

Question 33

How many grams are present in 0.885 moles of manganese?

A)62.1 g
B)48.6 g
C)21.5 g
D)27.5 g
E)0.016 g

Question 34

Determine the number of ammonia molecules in 4.85 g of ammonia.(N_A = 6.022 × 10²³ mol⁻¹)

A)2.92 × 10²³ molecules
B)4.73 × 10⁻²⁵ molecules
C)1.24 × 10²³ molecules
D)5.83 × 10⁻²⁴ molecules
E)1.71 × 10²³ molecules

Question 35

The density of water is 1.00 g/mL at 4°C.How many water molecules are present in 6.25 mL of water at this temperature? (N_A = 6.022 × 10²³ mol⁻¹)

A)6.27 × 10²³ molecules
B)3.76 × 10²⁴ molecules
C)2.09 × 10²³ molecules
D)6.02 × 10²³ molecules
E)0.347 molecules

Question 36

What is the mass of 7.80 × 10¹⁸ carbon atoms? (N_A = 6.022 × 10²³ mol⁻¹)

A)1.30 × 10⁻⁵ g
B)6.43 × 10³ g
C)7.80 × 10¹⁸ g
D)1.56 × 10⁻⁴ g
E)12.01 g

Question 37

What is the mass, in grams, of one arsenic atom? (N_A = 6.022 × 10²³ mol⁻¹)

A)5.48× 10⁻²³ g
B)33.0 g
C)74.9 g
D)1.24 × 10⁻²² g
E)8.04 × 10²¹ g

Question 38

Phosphorus pentachloride, a white solid that has a pungent, unpleasant odor, is used as a catalyst for certain organic reactions.Calculate the number of moles in 38.7 g of phosphorus pentachloride.

A)5.38 mol
B)3.55 mol
C)0.583 mol
D)0.282 mol
E)0.186 mol

Question 39

What is the mass in grams of 0.250 mol of the common antacid calcium carbonate?

A)4.0 × 10² g
B)25.0 g
C)17.0 g
D)4.00 × 10⁻² g
E)2.50 × 10⁻³ g

Question 40

Calculate the mass of 3.00 moles of CF₂Cl₂.

A)3.00 g
B)174 g
C)363 g
D)1.81 × 10²⁴ g
E)40.3

Question 41

Household sugar, sucrose, has the molecular formula C₁₂H₂₂O₁₁.What is the % of carbon in sucrose, by mass?

A)26.7%
B)33.3%
C)41.4%
D)42.1%
E)51.4%

Question 42

Determine the mass of Sr(C₂H₃O₂)₂ that contains 2.780 Χ 10²³ atoms of carbon.

A)205.7 g
B)57.19 g
C)46.16 g
D)94.96 g
E)23.74 g

Question 43

Proteins found in humans are polymers that consist of different combinations of 20 amino acids.Proline, one of the 20 amino acids, has the molecular formula, C₅H₉NO₂.If a human protein has 25 proline monomers, how many carbon atoms from proline are present in the protein?

A)4 C atoms
B)25 C atoms
C)40 C atoms
D)100 C atoms
E)125 C atoms

Question 44

Determine the number of oxygen atoms contained in 29.7 grams of Al₂(CO₃)₃.

A)6.88 × 10²³ O atoms
B)7.64 × 10²² O atoms
C)1.27 × 10²² O atoms
D)9.44 × 10²³ O atoms
E)4.37 × 10²³ O atoms

Question 45

Which of the following is an empirical formula of a compound that is 52.15 percent C, 13.13 percent H, and 34.73 percent O?

A)C₄H₁₂O₂
B)CH₆O₂
C)C₃HO₆
D)C₂H₆O
E)None of the answers is correct.

Question 46

How many nitrate ions are in 24.4 grams of Ca(NO₃)₂?

A)1.79 × 10²³ nitrate ions
B)0.149 nitrate ions
C)1.47 × 10²⁵ nitrate ions
D)8.95 × 10²² nitrate ions
E)0.297 nitrate ions

Question 47

Which of the following is the empirical formula for hexane, C₆H₁₄?

A)C₁₂H₂₈
B)C₆H₁₄
C)C₃H₇
D)CH_2.3
E)C_0.43H

Question 48

What is the mass percent of oxygen in barium perchlorate?

A)4.7%
B)8.5%
C)23.4%
D)38.1%
E)19.0%

Question 49

Which of the following is a molecular formula for a compound with an empirical formula of CH₂O and a molar mass of 150.g/mol?

A)C₇H₁₈O₃
B)C₅H₁₀O₅
C)C₃H₆O₃
D)CH₂O
E)None of the answers is correct.

Question 50

Smooth muscle myosin is a motor protein that plays a crucial role in the contraction of smooth muscle.If this protein has a molar mass of 480,000 grams/mol, what is the mass, in grams, of 27 moles of smooth muscle myosin?

A)1.8 × 10⁴ g
B)1.3 × 10⁷ g
C)1.8 × 10² g
D)2.8 × 10²⁹ g
E)None of the answers is correct.

Question 51

Which of the following is a molecular formula for a compound with an empirical formula of CH?

A)C₂H₆
B)C₃H₉
C)C₄H₁₀
D)C₆H₆
E)None of the answers is correct.

Question 52

What is the percent sulfur in iron(III) sulfate?

A)28%
B)32%
C)24%
D)48%
E)42%

Question 53

Determine the empirical formula of a compound that contains 1.409 moles of P and 3.52 moles of O in a particular sample.

A)PO₂
B)PO₃
C)P₂O₆
D)P₂O₅
E)P₂O₃

Question 54

What is the percent carbon in CH₃CH₂OH?

A)13%
B)26%
C)35%
D)46%
E)52%

Question 55

Calculate the mass in grams of 8.35 × 10²² molecules of CBr₄.

A)0.0217 g
B)0.139 g
C)7.21 g
D)12.7 g
E)46.0 g

Question 56

A compound is found to be 73.03% C, 6.13% H, and 20.84% O by mass.What is the empirical formula of the compound?

A)C₆H₆O
B)CHO
C)C₂H₂O
D)C₁₄H₁₄O₃
E)C₁₁HO₃

Question 57

Which of the following substances contains the greatest mass of carbon?

A)100 g CH₄
B)100 g C₂H₄
C)100 g CCl₄
D)100 g CH₂Cl₂
E)100 g CO₂

Question 58

Determine the mass of Al(C₂H₃O₂)₃ that contains 2.63 Χ 10²⁴ atoms of oxygen.

A)652 g
B)891 g
C)149 g
D)89.5 g
E)26.2 g

Question 59

What is the percent sodium in sodium carbonate?

A)43.4%
B)11.3%
C)45.3%
D)27.7%
E)21.7%

Question 60

A compound is found to be 15.65% H and 31.07% N, with the remainder from carbon, by mass.Determine the empirical formula of the compound.

A)N₄C₇H₂
B)NC₂H₇
C)NC₂H₈
D)N₂CH₃
E)NCH₅