Deck 6: Chemical Calculations: Formula Masses, Moles, and Chemical Equations

Question 1

Which of the following is the correct "set-up" for the problem "How many grams of S are present in 29.3 g of S₄N₄?" ?

A)
B)
C)
D)

Answer 1

Question 2

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

A) 9 mole of CO₂
B) 10 moles of Xe
C) 11 moles of N₂O
D) 12 moles of CO

Answer 2

11 moles of N₂O

Question 3

Which of the following statements concerning Avogadro's number is correct?

A) It has the value 6.02*10^-23.
B) It denotes the number of molecules in one mole of any molecular substance.
C) It is the mass, in grams, of one mole of any substance.
D) It denotes the number of atoms in one mole of any substance.

Answer 3

It denotes the number of molecules in one mole of any molecular substance.

Question 4

In which of the following molar quantities of sulfur would 5.95 * 10²⁴ atoms of sulfur be present?

A) 9.69 moles S
B) 9.79 moles S
C) 9.89 moles S
D) 9.99 moles S

Question 5

How many molecules of CO₂ are present in 33.6 g of CO₂?

A) 1.27 *10^-24
B) 4.60 *10²³
C) 8.90 *10²⁶
D) 7.22 *10²³

Question 6

To determine the formula mass of a compound you should:

A) Add up the atomic masses of all the atoms present.
B) Add up the atomic masses of all the atoms present and divide by the number of atoms present.
C) Add up the atomic numbers of all the atoms present.
D) Add up the atomic numbers of all the atoms present and divide by the number of atoms present.

Question 7

Which set of coefficients balances the equation C₄H₁₀ + O₂ $\rightarrow$ CO₂ + H₂O?

A) 1, 6, 4, 5
B) 1, 7, 4, 5
C) 1, 3, 4, 5
D) 2, 13, 8, 10

Question 8

In the following reaction, how many grams of H₂O are produced if 6.13 g of N₂H₄ react? N₂H₄ + 3O₂ 2NO₂ + 2H₂O

A) 1.72 g
B) 3.45 g
C) 12.3 g
D) 6.89 g

Question 9

Which of the following is the correct "setup" for the problem "How many atoms are present in 10.4 g Ge?"

A)
B)
C)
D)

Question 10

Which of the following is the correct "setup" for the problem "How many grams of H₂O will be produced from 2.1 moles of O₂ and an excess of H₂S?" according to the reaction 2H₂S + 3O₂ 2H₂O + 2SO₂

A)
B)
C)
D)

Question 11

The formula mass of ammonium phosphite, (NH₄)₃PO₃, is

A) 97.01 amu
B) 125.01 amu
C) 133.09 amu
D) 153.11 amu

Question 12

Which of the following samples has the largest mass, in grams?

A) 5 moles of CO₂
B) 6 moles of CN
C) 7 moles of H₂O
D) 8 moles of H₂

Question 13

Avogadro's number of sulfur (S) atoms would have a mass of

A) 6.02* 10^-23 g
B) 6.02 * 10²³ g
C) 16
D) 32

Question 14

A compound with the formula TeCl_n has a formula mass of 269.41 amu. What is the value for n in the formula TeCl_n?

A) 2
B) 3
C) 4
D) 6

Question 15

Which of following statements concerning theoretical yield, actual yield, and percent yield is correct?

A) Theoretical yield is a calculated number.
B) Actual yield is a calculated number.
C) A percent yield of greater than 50% is very difficult to obtain.
D) Percent yield is calculated by dividing the theoretical yield by the actual yield.

Question 16

Which of the following chemical equations is balanced?

A) 2H₂ + O₂ $\rightarrow$ H₂O
B) 2SO₂ + 2 O₂ $\rightarrow$ 3 SO₃
C) KClO₃ $\rightarrow$ KCl + 3 O₂
D) N₂ + 3H₂ $\rightarrow$ 2NH₃

Question 17

The "setup" for the problem, "What is the mass, in grams, of 5.69 *10¹⁹ atoms of Xe?" which follows is correct, except numbers in the middle conversion factor have been replaced by the letters A and B. What are the numerical values of A and B, respectively?

A) 1 and 6.02 * 10²³
B) 1 and 131.29
C) 6.02 * 10²³ and 1
D) 131.29 and 6.02 * 10²³

Question 18

Which one of the following conversion factors is not consistent with the equation: 4NH₃ + 5 O₂ $\rightarrow$ 4NO + 6H₂O

A)
B)
C)
D)

Question 19

Potassium forms an oxide with the formula K₂O. What is the coefficient of oxygen in the balanced equation for the reaction of potassium with oxygen to form this oxide?

A) 1
B) 2
C) 3
D) 4

Question 20

A mole of a chemical substance represents

A) the mass of the substance that will combine with 12.0 g of carbon
B) the mass of the substance that will combine with 100.0 g of oxygen
C) 6.02 * 10²³ chemical particles of the substance
D) 6.02 * 10^-23 grams of the substance

Question 21

The atomic masses of He and Be are 4.00 and 9.01 amu, respectively. Which of the following statements are true?

A) A mole of Be contains more atoms than a mole of He.
B) A mole of He is heavier than a mole of Be.
C) A mole of Be contains the same number of atoms as a mole of He.
D) More than one correct response.
E) No correct response.

Question 22

In which of the following pairings of masses does the first listed mass contain more moles of substance than the second listed mass?

A) 18.02 g H₂O and 18.02 g NH₃
B) 44.01 g CO₂ and 44.01 g CO
C) 105 g CH₄ and 105 g NO₂
D) more than one correct response
E) no correct response

Question 23

Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices: (1) Atoms are neither created nor destroyed in an ordinary chemical reaction.
(2) The mass of a mole of a substance depends on the identity of the substance.
(3) One mole of O₂ molecules contains 6.02 * 10²³ molecules.

A) All three statements are true.
B) Two of the three statements are true.
C) Only one of the statements is true.
D) None of the statements is true.

Question 24

Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices: (1) 3.0 moles of CO has a greater mass, in grams, than does 2.0 moles of CO₂.
(2) In a balanced chemical equation, there must be the same total number of molecules on each side of the equation.
(3) The molar mass and formula mass for a compound have different units but the same numerical value.

A) All three statements are true.
B) Two of the three statements are true.
C) Only one of the statements is true.
D) None of the statements is true.

Question 25

A mole of a chemical substance represents

A) the formula mass of that substance expressed in atomic mass units
B) Avogadro's number of grams of that substance
C) the mass of that substance that will combine with 1.00 gram of carbon
D) more than one correct response
E) no correct response

Question 26

Which of the following substances has a formula mass that is greater than 80.0 amu?

A) Cl₂O
B) OF₂
C) SO₂
D) more than one correct response
E) no correct response

Question 27

Which of the following equations is balanced?

A) FeS + 2HBr $\rightarrow$ FeBr₂ + 2H₂S
B) PbO₂ + 2H₂ $\rightarrow$ Pb + 2H₂O
C) Fe₂O₃ + 3H₂ $\rightarrow$ 2Fe + 3H₂O
D) more than one correct response
E) no correct response

Question 28

Which of the following statements is true for all balanced equations?

A) The total number of molecules on each side must be equal.
B) The sum of the subscripts on each side must be equal.
C) The sum of the coefficients on each side must be equal.
D) More than one correct response.
E) No correct response.

Question 29

Which of the following quantities must be known before the percent yield of a product Q can be calculated?

A) theoretical yield of Q
B) actual yield of Q
C) number of other products produced besides Q
D) more than one correct response
E) no correct response

Question 30

Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices: (1) 2.0 moles of NO contains the same number of oxygen atoms as 1.0 mole of CO₂.
(2) The coefficients in a balanced equation give the fixed molar ratios between reactants and products.
(3) Avogadro's number is an experimentally determined quantity.

A) All three statements are true.
B) Two of the three statements are true.
C) Only one of the statements is true.
D) None of the statements is true.

Question 31

One mole of H₂SO₄ contains

A) two moles H atoms
B) four moles S atoms
C) seven moles of atoms
D) more than one correct response
E) no correct response

Question 32

The balanced equation C + O₂ $\rightarrow$ CO₂ tells us that 24.02 g of C will exactly react with

A) 32.00 g of O₂
B) 2.000 moles of O₂
C) 6.02 * 10²³ molecules of O₂
D) more than one correct response
E) no correct response

Question 33

The balanced equation 2CO + O₂ $\rightarrow$ 2CO₂ tells us that:

A) One gram of O₂ will produce two grams of CO₂.
B) Two molecules of CO will react with one molecule of O₂.
C) One mole of CO will produce two moles of CO₂.
D) More than one correct response.
E) No correct response.

Question 34

For which of the following compounds does 1.9 g represent 4.3 * 10^-2 moles of compound?

A) CO₂
B) C₃H₈
C) H₂O₂
D) more than one correct response
E) no correct response

Question 35

Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices: (1) The molar mass of an element, in the solid state, has the same numerical value as the element's atomic mass.
(2) In a balanced chemical equation, the number of reactants must equal the number of products.
(3) One mole of N₂O₄ contains six moles of atoms.

A) All three statements are true.
B) Two of the three statements are true.
C) Only one of the statements is true.
D) None of the statements is true.

Question 36

Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices: (1) In the notation 2H₂O, the 2 out in front is called a coefficient.
(2) Atomic masses and formula masses are specified using the same units.
(3) In a formula-based "grams of A to grams of B" problem, molar masses are needed in each of the first two conversion factors.

A) All three statements are true.
B) Two of the three statements are true.
C) Only one of the statements is true.
D) None of the statements is true.

Question 37

In which of the following groups of substances do all members of the group have atomic masses that are within 1.00 amu of each other?

A) CH₄, NH₃, H₂O
B) CO, N₂, NO
C) C₃H₈, CO₂, N₂O
D) more than one correct response
E) no correct response

Question 38

Which of the following samples has a mass greater than 50.00 grams?

A) 6.02 *10²³ atoms of Fe
B) 3.01 * 10²³ molecules of CH₄
C) 9.03 * 10²³ molecules of H₂O
D) more than one correct response
E) no correct response

Question 39

Avogadro's number is equal to the number of

A) atoms in one mole of N₂
B) molecules in one mole of N₂O₄
C) atoms in one-half mole of CO
D) more than one correct response
E) no correct response

Question 40

In which of the following unbalanced equations are five moles of reactants required to produce two moles of products?

A) Na + N₂ $\rightarrow$ NaN₃
B) Al + S $\rightarrow$ Al₂S₃
C) N₂ + H₂ $\rightarrow$ NH₃
D) more than one correct response
E) no correct response

Question 41

Select the correct numerical value for the mass, in grams, of 6.02 * 10²³ atoms of C.

A) 12.0
B) 24.0
C) 44.0
D) 88.0

Question 42

Select the correct numerical value for the number of moles of S in two moles of H₂SO₄.

A) 1
B) 2
C) 6
D) 12

Question 43

Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices: (1) Six mole-to-mole relationships are obtainable from a balanced chemical equation involving two reactants and two products.
(2) The compound H₂O has a greater formula mass than does the compound NH₃.
(3) The atomic mass unit (amu) and the gram unit (g) are related to one another through Avogadro's number.

A) All three statements are true.
B) Two of the three statements are true.
C) Only one of the statements is true.
D) None of the statements is true.

Question 44

Contrast the magnitudes, to three significant figures, (I) atoms in three moles of CO, (II) atoms in two moles of CO₂, and then select an appropriate response from the response list.

A) I is greater than II
B) I is equal to II
C) I is less than II
D) I and II cannot be compared because of insufficient information

Question 45

Select the correct numerical value for the atomic mass, in amu, of C.

A) 12.0
B) 24.0
C) 44.0
D) 88.0

Question 46

Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices: (1) Two moles of O₂ molecules contain twice Avogadro's number of atoms.
(2) The actual yield of a product in a chemical reaction is a measured rather than calculated quantity.
(3) In an equation-based "grams of A to grams of B" problem, equation coefficients become part of the first needed conversion factor.

A) All three statements are true.
B) Two of the three statements are true.
C) Only one of the statements is true.
D) None of the statements is true.

Question 47

Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices: (1) Avogadro's number is part of the conversion factor needed to solve a "moles of A to grams of A" problem.
(2) The sum of the coefficients in the balanced equation for the production of water from hydrogen gas and oxygen gas is five.
(3) 2.00 moles of NH₃ molecules have a mass of 34.0 grams.

A) All three statements are true.
B) Two of the three statements are true.
C) Only one of the statements is true.
D) None of the statements is true.

Question 48

Select the correct numerical value for the molar mass, in grams, of CO₂.

A) 12.0
B) 24.0
C) 44.0
D) 88.0

Question 49

Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices: (1) In balancing an equation, formula subscripts are adjusted as needed to obtain the balance.
(2) 1.00 mole of C contains the same number of atoms as does 12.0 g of C.
(3) Both a microscopic and macroscopic levels of interpretation exist for a chemical formula with the former involving atoms and the latter involving molecules.

A) All three statements are true.
B) Two of the three statements are true.
C) Only one of the statements is true.
D) None of the statements is true.

Question 50

Select the correct numerical value for the number of moles of atoms in two moles of SO₂.

A) 1
B) 2
C) 6
D) 12

Question 51

Contrast the magnitudes, to three significant figures, (I) molecules in 28.0 g of N_2, (II) molecules in 28.0 g of O₂, and then select an appropriate response from the response list.

A) I is greater than II
B) I is equal to II
C) I is less than II
D) I and II cannot be compared because of insufficient information

Question 52

Select the correct numerical value for the number of moles of H in one mole of (NH₄)₃PO₄.

A) 1
B) 2
C) 6
D) 12

Question 53

Characterize EACH of the three given statements as being TRUE or FALSE and then indicate the collective true-false status of the statements using the choices: (1) Carbon monoxide reacts with hemoglobin in red blood cells to produce carbon dioxide, which changes blood's acidity.
(2) Sulfuric acid is the number two chemical in the United States in terms of production amount.
(3) The raw materials needed for industrial sulfuric acid production are sulfur, air and water.

A) All three statements are true.
B) Two of the three statements are true.
C) Only one of the statements is true.
D) None of the statements is true.

Question 54

Contrast the magnitudes, to three significant figures, (I) moles in 28.0 g of N_2, (II) moles in 28.0 g of CO, and then select an appropriate response from the response list.

A) I is greater than II
B) I is equal to II
C) I is less than II
D) I and II cannot be compared because of insufficient information

Question 55

Select the correct numerical value for the formula mass, in amu, of CO₂.

A) 12.0
B) 24.0
C) 44.0
D) 88.0

Question 56

Select the correct numerical value for the number of moles of O atoms in three moles of O₂

A) 1
B) 2
C) 6
D) 12

Question 57

Contrast the magnitudes, to three significant figures, (I) molecules in two moles of CO, (II) molecules in two moles of CO₂, and then select an appropriate response from the response list.

A) I is greater than II
B) I is equal to II
C) I is less than II
D) I and II cannot be compared because of insufficient information

Question 58

Select the correct numerical value for the number of moles of O₂ molecules in two moles of O₂.

A) 1
B) 2
C) 6
D) 12

Question 59

Contrast the magnitudes, to three significant figures, (I) mass of one mole of CO₂, (II) the mass of one mole of NH₃, and then select an appropriate response from the response list.

A) I is greater than II
B) I is equal to II
C) I is less than II
D) I and II cannot be compared because of insufficient information

Question 60

Select the correct numerical value for the mass, in grams, of 2.00 moles of CO₂

A) 12.0
B) 24.0
C) 44.0
D) 88.0

Question 61

Select the set of coefficients from the response list that correctly balances the equation. __H₂ + N₂ $\rightarrow$ NH₃

A) 1, 1, 2
B) 1, 2, 1
C) 2, 1, 2
D) 3, 1, 2

Question 62

Using the balanced equation for the combustion of ethane: 2C₂H₆ + 7 O₂ $\rightarrow$ 4CO₂ + 6H₂O, how many moles of O₂ needed to produce 12 moles of H₂O?

A) 6
B) 7
C) 8
D) 14

Question 63

Select the set of coefficients from the response list that correctly balances the equation. __SO₂ + O₂ $\rightarrow$ SO₃

A) 1, 1, 2
B) 1, 2, 1
C) 2, 1, 2
D) 3, 1, 2

Question 64

Select the set of coefficients from the response list that correctly balances the equation. __N₂ + O₂ $\rightarrow$ NO

A) 1, 1, 2
B) 1, 2, 1
C) 2, 1, 2
D) 3, 1, 2

Question 65

Using the balanced equation for the combustion of ethane: 2C₂H₆ + 7 O₂ $\rightarrow$ 4CO₂ + 6H₂O, how many molecules of CO₂ produced when four molecules of C₂H₆ react?

A) 6
B) 7
C) 8
D) 14

Question 66

Select the set of coefficients from the response list that correctly balances the equation. __CO + O₂ $\rightarrow$ CO₂

A) 1, 1, 2
B) 1, 2, 1
C) 2, 1, 2
D) 3, 1, 2

Question 67

Using the balanced equation for the combustion of ethane: 2C₂H₆ + 7 O₂ $\rightarrow$ 4CO₂ + 6H₂O, how many moles of O₂ that react with four moles of C₂H₆?

A) 6
B) 7
C) 8
D) 14

Question 68

Using the balanced equation for the combustion of ethane: 2C₂H₆ + 7 O₂ $\rightarrow$ 4CO₂ + 6H₂O, how many molecules of O₂ that react with two molecules of C₂H₆?

A) 6
B) 7
C) 8
D) 14

Question 69

Using the balanced equation for the combustion of ethane: 2C₂H₆ + 7 O₂ $\rightarrow$ 4CO₂ + 6H₂O, how many moles of CO₂ produced at the same time nine moles of H₂O are produced?

A) 6
B) 7
C) 8
D) 14

Question 70

Select the set of coefficients from the response list that correctly balances the equation. __CH₄ $\rightarrow$ __C₃H₈ + __H₂

A) 1, 1, 2
B) 1, 2, 1
C) 2, 1, 2
D) 3, 1, 2