Deck 3: Calculations With Chemical Formulas and Equations

Question 1

What is the molar mass of ammonium sulfite,(NH₄)₂SO₃?

A)98 g/mol
B)116 g/mol
C)55 g/mol
D)180 g/mol
E)84 g/mol

Answer 1

116 g/mol

Question 2

How many atoms of carbon are there in 0.37 mol of procaine,C₁₃H₂₀N₂O₂,a "pain killer" used by dentists?

A)4.8 × 10²³
B)3.1 × 10²⁴
C)2.9 × 10²⁴
D)4.5 × 10²³
E)3.3 × 10²⁴

Answer 2

2.9 × 10²⁴

Question 3

Which of the following compounds contains the largest number of atoms?

A)4.0 mol of H₂S
B)3.0 mol of NO₃
C)2.0 mol of Na₂SO₄
D)5.0 mol of HBr
E)1.0 mol of CH₃COOH

Answer 3

2.0 mol of Na₂SO₄

Question 4

Monodisperse polyacrylonitrile contains molecules with the general formula -(CH₂CHCN)_n-,where n is typically greater than 10,000.Given that a sample of monodisperse polyacrilonitrile weighs 676.8 g and contains molecules of -(CH₂CHCN)_n-,calculate n.

A)
B)
C)
D)
E)

Question 5

What is the formula mass of barium phosphate,Ba₃(PO₄)₂?

A)506.95 amu
B)570.95 amu
C)232.30 amu
D)1013.90 amu
E)601.92 amu

Question 6

A 1.74 g sample of an element contains 7.887 ×10²¹atoms.What is the element symbol?

A)​Cs
B)​I
C)​In
D)​Sb
E)​Cd

Question 7

Plastic wrap can be made from poly(vinylidene chloride).A single poly(vinylidene chloride)strand has the general formula -(CH₂CHCl)_n-,where n ranges from 10,000 to 100,000.What is the molar mass of a single poly(vinylidene chloride)molecule containing repeating units?

A) g/mol
B) g/mol
C) g/mol
D) g/mol
E) g/mol

Question 8

The formula mass of aluminum oxalate,Al₂(C₂O₄)₃,is

A)143 amu.
B)318 amu.
C)290 amu.
D)204 amu.
E)197 amu.

Question 9

What is the molecular mass of cycloheptane,C₇H₁₄?

A)13.02 amu
B)1191.19 amu
C)85.08 amu
D)98.19 amu
E)26.12 amu

Question 10

The dicarboxylic acid potassium hydrogen pthalate (shown in the figure)is used to standardize solutions of strong base.What is the molar mass of this compound?

A)204.2 g/mol
B)192.2 g/mol
C)248.9 g/mol
D)71.08 g/mol
E)172.2 g/mol

Question 11

The formula mass of zinc acetate trihydrate,Zn(CH₃COO)₂ • 3H₂O,is

A)356 amu.
B)184 amu.
C)292 amu.
D)238 amu.
E)156 amu.

Question 12

The hydrocarbon octane has the structural formula CH₃(CH₂)₆CH₃.What is the molecular mass of this hydrocarbon?

A)114.2 amu.
B)0.008754 amu.
C)100.1 amu.
D)0.009984432 amu.
E)124.2 amu.

Question 13

What is the molecular mass of the hydrocarbon styrene (shown in the figure)?

A)104.1 amu.
B)91.1 amu.
C)103.1 amu.
D)13.0 amu.
E)78.1 amu.

Question 14

What is the mass in grams of one propene,C₃H₆,molecule?

A)6.99× 10^-23 g
B)2.53 × 10²⁵ g
C)44.0 g
D)42.0 g
E)1.99 × 10^-23 g

Question 15

The fully hydrated form of sodium sulfate is the decahydrate,Na₂SO₄ • 10H₂O.When heated the hydrated salt loses water.How many water molecules are found per formula unit in a partially dehydrated sample of sodium sulfate with a formula mass of 197 amu (i.e.find n for Na₂SO₄ • nH₂O)?

A)3 waters.
B)5 waters.
C)7 waters.
D)9 waters.
E)4 waters.

Question 16

The molecular formula of a particular solid is C₈H₄O₆.Its molecular mass is

A)288 amu.
B)100 amu.
C)296 amu.
D)196 amu.
E)170 amu.

Question 17

What is the mass of carbon in grams found in one molecule of the compound C₇H₈O₄?

A) g
B) g
C) g
D) g
E)156.000000 g

Question 18

A single molecule of polystryene has the repeating unit -[CH₂CH(C₆H₅)]_n-,where n is the number of repeating units.What is the value of n if the molecular mass of a single polymer chain is amu?

A) units.
B) units.
C) units.
D) units.
E) units.

Question 19

Monodisperse polyacrylonitrile contains molecules with the general formula -(CH₂CHCN)_n-,where n is typically greater than 10,000.Given that a sample of monodisperse polyacrylonitrile weighs 665.1 g and contains molecules of -(CH₂CHCN)_n-,what is the molar mass of the polymer?

A) g/mol
B) g/mol
C) g/mol
D) g/mol
E) g/mol

Question 20

What is the molar mass of the solid C₆H₈N₂O₄?

A)144 g/mol
B)108 g/mol
C)172 g/mol
D)90 g/mol
E)164 g/mol

Question 21

What is the mass of oxygen atoms in 0.380 mol Fe(CO)₅?

A)21.2 g
B)74.4 g
C)30.4 g
D)6.08 g
E)22.8 g

Question 22

How many moles of silver are contained in 7.00 kg of silver?

A)64.9 mol
B)64.9 × 10¹ mol
C)64.9 × 10^-3 mol
D)64.9 × 10³ mol
E)64.9 × 10^-1 mol

Question 23

How many molecules are there in 1.54 kg of hydrazine,N₂H₄?

A)4.81 × 10²³
B)2.90 × 10²⁵
C)1.88 × 10²²
D)1.54 × 10²⁶
E)2.56 × 10²¹

Question 24

What is the mass in grams of 0.754 mol of glucose,C₆H₁₂O₆?

A)0.00419 g
B)72.4 g
C)136 g
D)22.6 g
E)239 g

Question 25

Which of the following contains the greatest mass of oxygen atoms?

A)0.5 mol CoSO₄ • 7H₂O
B)2.1 mol KHSO₄
C)1.1 mol K₂Cr₂O₇
D)2.1 mol H₂O₂
E)2.1 mol Na₂S₂O₃

Question 26

Sodium cyclamate,C₆H₁₁NHSO₃Na,was used at one time as an artificial sweetener.C₆H₁₁NHSO₃Na has a molecular mass of 201.2 g/mol.How many moles of sodium cyclamate are contained in a 56.0-g sample?

A)0.175 mol
B)0.160 mol
C)0.278 mol
D)0.255 mol
E)%1,0f mol

Question 27

How many moles of pentane,C₅H₁₂,are contained in a 31-g sample?

A)0.52 mol
B)0.43 mol
C)0.74 mol
D)3.9 mol
E)3.1 mol

Question 28

Calculate the number of moles of bromine present in 20.5 mL of Br₂(l),whose density is 3.12 g/mL.

A)2.50 mol
B)0.257 mol
C)0.801 mol
D)0.128 mol
E)0.400 mol

Question 29

Sorbose,C₆H₁₂O₆,is used in making vitamin C.A sorbose sample containing 36.0 g of carbon atoms also contains ____ g of hydrogen atoms.

A)12
B)6.04
C)4.32 × 10²
D)36
E)2.99

Question 30

A 0.0106-mol sample of urea,NH₂CONH₂,contains

A)6.02 × 10²³ molecules.
B)2.55 × 10²² molecules.
C)5.10 × 10²² atoms.
D)2.55 × 10²³ atoms.
E)1.06 × 10²⁴ atoms.

Question 31

How many molecules are there in 104 g of pentylene glycol,HO(CH₂)₅OH?

A)1
B)(6.02 × 10²³)/104
C)104
D)104 × (6.02 × 10²³)
E)6.02 × 10²³

Question 32

Consider the following three samples.
A.A sample containing 180 g glucose (C₆H₁₂O₆)
B.A sample containing 90 g glucose and 90 g mannose (C₆H₁₂O₆)
C.A sample containing 180 g mannose
Which statement is correct?

A)All three samples have the same number of oxygen atoms.
B)Both samples A and C have the same number of oxygen atoms,but more than in sample B.
C)Sample B has more oxygen atoms than sample A or sample C.
D)Sample C has more oxygen atoms than sample A or sample B
E)Sample A has more oxygen atoms than sample B or sample C.

Question 33

How many moles of hexachlorobenzene,C₆Cl₆,are in 5.44 g of C₆Cl₆?

A)0.0254 mol
B)1.55 × 10³ mol
C)0.0755 mol
D)0.019 mol
E)0.0394 mol

Question 34

In 0.266 mol of trimellitic acid,C₆H₃(COOH)₃,there are

A)1.60 × 10²² molecules.
B)6.41 × 10²⁴ molecules.
C)4.80 × 10²³ oxygen atoms.
D)1.44 × 10²⁴ carbon atoms.
E)2.67 × 10²³ hydrogen atoms.

Question 35

How many molecules are there in 60 g of acetic acid,C₂H₄O₂?

A)(6.02 × 10²³)/ 60
B)60
C)6.02 × 10²³
D)30
E)60 × (6.02 × 10²³)

Question 36

How many moles of iron atoms are contained in 4.16 g of iron?

A)232 mol
B)0.0548 mol
C)0.0745 mol
D)0.116 mol
E)0.160 mol

Question 37

A sample of ammonium phosphate,(NH₄)₃PO₄,contains 0.104 mol of nitrogen atoms.The number of moles of oxygen atoms in the sample is

A)0.139 mol.
B)0.0104 mol.
C)0.41 mol.
D)0.419 mol.
E)4.6 mol.

Question 38

A sample of thallium(III)peroxide,Tl₂(O₂)₃,contains 2.45 mol of thallium(III)ions.The number of moles of peroxide ions in the sample is

A)3.67 mol.
B)1.63 mol.
C)2.45 mol.
D)7.35 mol.
E)4.9361 mol.

Question 39

Which one of the following samples has the greatest mass?

A)0.37 mol of camphor,C₁₀H₁₆O
B)4.2 mol of ammonia,NH₃
C)9.3 mol of krypton,Kr
D)4.0 mol of iodine vapor,I₂
E)1.6 mol of formaldehyde,CH₂O

Question 40

Styrene's empirical formula is CH.What mass of styrene contains 2.95 × 10²¹ atoms of hydrogen? The molar mass of styrene is 104 g/mol.

A)0.0391 g
B)0.0636 g
C)0.509 g
D)0.0587 g
E)0.00489 g

Question 41

An ore sample with a mass of 92.3 g is found to contain 17.7% by mass iron.What mass of iron is contained in the ore?

A)16.300000 g
B)78.4 g
C)1.77 g
D)82.2 g
E)464 g

Question 42

Which of the following samples contains the smallest number of molecules?

A)5.00 g of TNT,C₇H₅N₃O₆
B)5.00 g of benzene,C₆H₆
C)5.00 g of glucose,C₆H₁₂O₆
D)5.00 g of naphthalene,C₁₀H₈
E)5.00 g of formaldehyde,CH₂O

Question 43

The mineral leadhillite,which is essentially Pb₄(SO₄)(CO₃)₂(OH)₂ (FW = 1079 g/mol),contains ____% hydrogen by mass.

A)76.81
B)0.1868
C)2.226
D)17.79
E)2.971

Question 44

Which of the following samples contains the largest number of atoms?

A)1 g N₂
B)1 g Be
C)1 g Br₂
D)1 g P₄
E)1 g Si

Question 45

How many molecules are there in 2.10 mg of mannose,C₆H₁₂O₆,which is a sweet-tasting sugar that has a bitter aftertaste?

A)5.16 × 10²¹
B)2.87 × 10²¹
C)6.32 × 10¹⁸
D)3.49 × 10²⁴
E)7.02 × 10¹⁸

Question 46

The total number of oxygen atoms in 1.93 g of CaCO₃ (MM = 100.0 g/mol)is

A)2.24 × 10²³.
B)4.65 × 10²².
C)3.49 × 10²².
D)1.92 × 10²³.
E)5.81 × 10²².

Question 47

What is the percentage by mass of chlorine in the insecticide Lindane,C₆H₆Cl₆?

A)20.6 %
B)1.00 %
C)69.6 %
D)8.80 %
E)73.1 %

Question 48

Which one of the following contains 4.21 × 10²⁴ atoms?

A)91 g C₂H₂
B)168 g O₂
C)56 g CH₄
D)294 g N₂
E)28 g He

Question 49

In 0.300 mol of dimethylhydrazine,(CH₃)₂N₂H₂,there are

A)1.81 × 10²⁴ molecules.
B)2.51 × 10²³ atoms.
C)1.81 × 10²² molecules.
D)2.17 × 10²⁴ atoms.
E)1.08 × 10²⁴ atoms.

Question 50

An ore sample is found to contain 10.500000 g of cobalt and 87.3 g waste rock (gangue).What is the percent by mass of cobalt in the ore?

A)10.7 %
B)12.114 %
C)0.107 %
D)0.12228 %
E)1.2879 %

Question 51

A sample of 496 g of white phosphorus,P₄,contains the same number of atoms as

A)192 g of ozone (O₃).
B)56 g of nitrogen (N₂).
C)92 g of sodium.
D)120 g of formaldehyde (CH₂O).
E)128 g of oxygen (O₂).

Question 52

How many atoms are present in 495 g of KPF₆ (MM = 184.1 g/mol)?

A)2.38 × 10²⁵
B)1.62 × 10²¹
C)2.69 × 10²¹
D)1.21 × 10²⁶
E)1.29 × 10²⁵

Question 53

Styrene's empirical formula is CH.When it is heated to 200°C,it is converted into a polymer,polystyrene,which has excellent insulating properties.What mass of styrene contains 1.77 × 10²¹ molecules of styrene? The molar mass of styrene is 104 g/mol.

A)0.00293 g
B)0.305 g
C)0.587 g
D)0.0382 g
E)0.0235 g

Question 54

Which is a reasonable mass corresponding to 10²⁶ molecules of a substance?

A)100 ng
B)100 g
C)100 mg
D)100 kg
E)100 µg

Question 55

Which of the following compounds has the highest percentage of hydrogen atoms by mass?

A)CH₃COOH
B)C₂H₅OH
C)CH₃OH
D)H₂CO₃
E)H₂C₂O₄

Question 56

How many aluminum atoms are there in 52 g of Al₂S₃?

A)4.2 × 10²³
B)1.6 × 10²¹
C)2.1 × 10²³
D)1.1 × 10²¹
E)6.3 × 10²³

Question 57

A sample of 96 g of ozone,O₃,contains the same number of atoms as

A)96 g of oxygen (O₂).
B)8.06 g of hydrogen (H₂).
C)76 g of fluorine (F₂).
D)54 g of aluminum (Al).
E)117 g of nickel (Ni).

Question 58

What is the percent by mass nitrogen in (NH₄)₂SO₃?

A)24.1 %
B)12.961 %
C)64.6 %
D)39.3 %
E)4.73 %

Question 59

Which of the following compounds has the highest percentage of nitrogen by mass?

A)(NH₄)₂SO₃
B)NaNO₃
C)N₂F₄
D)NH₄NO₂
E)HNO₃

Question 60

In 1928,1.0 g of rhenium,Re,was isolated from 660 kg of the ore molybenite.The percent by mass of this element in the molybenite was

A)0.66 %.
B)0.15 %.
C)3.5 × 10^-4 %.
D)6.6 × 10^-3 %.
E)1.5 × 10^-4 %.

Question 61

Which of the following is the empirical formula for the molecule below?

A)CHO
B)CH₃COOH
C)C₂H₄O₂
D)CH₂O
E)none of the above.

Question 62

Analysis of a compound showed that it contained 76.0 % fluorine atoms and 24.0 % carbon atoms by mass.What is its empirical formula?

A)CF₂
B)C₂F₃
C)CF₃
D)C₂F₅
E)CF

Question 63

A sample of an oxide of antimony (Sb)contained 48.5 g of antimony combined with 15.9 g of oxygen.What is the simplest formula for the oxide?

A)SbO₂
B)SbO
C)Sb₂O₃
D)Sb₃O
E)Sb₂O₅

Question 64

A 4.215 g sample of a compound containing only carbon,hydrogen,and oxygen is burned in an excess of dioxygen,producing 9.582 g CO₂ and 3.922 g H₂O.What percent by mass of oxygen is contained in the original sample?

A)27.54 %
B)32.75 %
C)12.73 %
D)13.42 %
E)6.939 %

Question 65

NaHCO₃ is the active ingredient in baking soda.How many grams of oxygen are present in 0.25 g of NaHCO₃?

A)0.009 g
B)0.048 g
C)2.98 × 10³ g
D)0.016 g
E)0.14g

Question 66

Of the following,the only empirical formula is

A)C₄H₁₀.
B)C₄H₈.
C)C₅H₁₄.
D)H₂O₂.
E)O₃.

Question 67

Which of the following contains the greatest mass of bromine atoms?

A)15.0 g of KBr
B)29.0 g of Br₂
C)0.096 mol of KBr
D)0.078 mol of Br₂
E)25.0 g of NaBrO₃

Question 68

How many grams of potassium are present in 28.7 g of K₂Cr₂O₇?

A)7.63 g
B)1.468 g
C)3.81 g
D)78.2 g
E)14.4 g

Question 69

A 3.391 g sample of a compound containing only carbon,hydrogen,and oxygen is burned in an excess of dioxygen,producing 6.477 g CO₂ and 3.978 g H₂O.What mass of oxygen is contained in the original sample?

A)1.178 g
B)1.4899 g
C)3.086 g
D)2.499 g
E)0.5874 g

Question 70

What is the mass percentage of carbon in the compound C₆H₆O₃?

A)4.8 %
B)61.9 %
C)57.1 %
D)38.1 %
E)20.0 %

Question 71

A 4.957 g sample of a hydrocarbon is burned in an excess of dioxygen,producing 9.284 g CO₂ and water.What mass of hydrogen is contained in the original sample?

A)2.423 g
B)4.327 g
C)14.24 g
D)1.794 g
E)2.478 g

Question 72

A compound containing only carbon,hydrogen,and oxygen is subjected to elemental analysis.Upon complete combustion,a 0.7916-g sample of the compound produced 1.581 g of CO₂ and 0.6474 g of H₂O.What is the empirical formula of the compound?

A)C₃H₆O₃
B)C₃H₃O
C)C₂H₄O
D)C₂H₂O
E)CH₂O₃

Question 73

Which of the following compounds has the same percentage of carbon and hydrogen by mass as cyclohexane,C₆H₁₂?

A)C₆H₁₄,hexane
B)C₄H₈,butylene
C)C₆H₁₀,cyclohexene
D)C₆H₆,benzene
E)C₆H₁₂O₆,glucose

Question 74

A sample containing only carbon,hydrogen,phosphorus,and oxygen is subjected to elemental analysis.After complete combustion,a 0.3584-g sample of the compound yields 0.5139 g of CO₂,0.3155 g of H₂O,and 0.2762 g of P₄O₁₀.What is the empirical formula of the compound?

A)CH₃PO
B)C₂H₃PO
C)C₂H₆P₂O₄
D)C₃H₉PO
E)CH₂P₄O₁₃

Question 75

A 3.903 g sample of a hydrocarbon is burned in an excess of dioxygen,producing 7.31177 g CO₂ and 4.488 g H₂O.What is the empirical formula of the hydrocarbon?

A)CH₃
B)CH₂
C)C₂H₃
D)CH₄
E)CH

Question 76

A crystal of the mineral troegerite,(UO₂)₃(AsO₄)₂ • 12H₂O (FM = 1304 amu),contains ____% uranium by mass.

A)18.6
B)47.2
C)62.8
D)30.0
E)54.8

Question 77

How many grams of hydrogen atoms are present in 16.4 g of water?

A)33.1 g
B)0.91 g
C)1.84 g
D)2.20 g
E)10.9 g

Question 78

A sample containing only carbon,hydrogen,and silicon is subjected to elemental analysis.After complete combustion,a 0.7020-g sample of the compound yields 1.4 g of CO₂,0.86 g of H₂O,and 0.478 g of SiO₂.What is the empirical formula of the compound?

A)CH₃Si
B)C₂H₄Si
C)C₄H₁₂Si
D)C₆H₁₂Si₂
E)CH₂Si

Question 79

A 0.4647-g sample of a compound known to contain only carbon,hydrogen,and oxygen was burned in dioxygen to yield 0.01962 mol of CO₂ and 0.01961 mol of H₂O.What is the empirical formula of the compound?

A)CHO
B)C₃H₃O₂
C)C₂H₂O
D)C₃H₆O₂
E)C₆H₃O₂

Question 80

What is the percentage by mass of nitrogen in ammonium phosphate,(NH₄)₃PO₄?

A)28.1 %
B)14.15 %
C)52.4 %
D)39.9 %
E)2.27 %