Central Science: Chapter 3 Flashcards

When the following equation is balanced, the coefficients are ________.

C8H18 + O2 → CO2 + H2O

A) 2, 3, 4, 4
B) 1, 4, 8, 9
C) 2, 12, 8, 9
D) 4, 4, 32, 36
E) 2, 25, 16, 18

Of the reactions below, which one is not a combination reaction?
A) C + O2 → CO2
B) 2Mg + O2 → 2MgO
C) 2N2 + 3H2 → 2NH3
D) CaO + H2O → Ca(OH)2
E) 2CH4 + 4O2 → 2CO2 + 4H2O

When a hydrocarbon burns in air, what component of air reacts?
A) oxygen
B) nitrogen
C) carbon dioxide
D) water
E) argon

When a hydrocarbon burns in air, a component produced is ________.
A) oxygen
B) nitrogen
C) carbon
D) water
E) argon

Of the reactions below, which one is a decomposition reaction?
A) NH4Cl → NH3 + HCl
B) 2Mg + O2 → 2MgO
C) 2N2 + 3H2 → 2NH3
D) 2CH4 + 4O2 → 2CO2 + 4H2O
E) Cd(NO3)2 + Na2S → CdS + 2NaNO3

Which one of the following substances is the product of this combination reaction?

Al (s) + I2(s) → ________

A) AlI2
B) AlI
C) AlI3
D) Al2I3
E) Al3I2

Which one of the following is not true concerning automotive air bags?
A) They are inflated as a result of a decomposition reaction.
B) They are loaded with sodium azide initially.
C) The gas used for inflating them is oxygen.
D) The two products of the decomposition reaction are sodium and nitrogen.
E) A gas is produced when the air bag activates.

The reaction used to inflate automobile airbags ________.
A) produces sodium gas
B) is a combustion reaction
C) is a combination reaction
D) violates the law of conservation of mass
E) is a decomposition reaction

Which of the following are combination reactions?
1) CH4 (g) + O2 (g) → CO2 (g) + H2O (l)
2) CaO (s) + CO2 (g) → CaCO3 (s)
3) Mg (s) + O2(g) → MgO (s)
4) PbCO3 (s) → PbO (s) + CO2 (g)
A) 1, 2, and 3
B) 2 and 3
C) 1, 2, 3, and 4
D) 4 only
E) 2, 3, and 4

Which of the following are combustion reactions?
1) CH4 (g) + O2 (g) → CO2 (g) + H2O (l)
2) CaO (s) + CO2 (g) → CaCO3 (s)
3) PbCO3 (s) → PbO (s) + CO2 (g)
4) CH3OH (l) + O2 (g) → CO2 (g) + H2O (l)
A) 1 and 4
B) 1, 2, 3, and 4
C) 1, 3, and 4
D) 2, 3, and 4
E) 3 and 4

Which of the following are decomposition reactions?
1) CH4 (g) + O2 (g) → CO2 (g) + H2O (l)
2) CaO (s) + CO2 (g) → CaCO3 (s)
3) Mg (s) + O2(g) → MgO (s)
4) PbCO3 (s) → PbO (s) + CO2 (g)
A) 1, 2, and 3
B) 4 only
C) 1, 2, 3, and 4
D) 2 and 3
E) 2, 3, and 4

The formula of nitrobenzene is C6H5NO2. The molecular weight of this compound is ________ amu.
A) 107.11
B) 43.03
C) 109.10
D) 123.11
E) 3.06

The formula weight of potassium dichromate (K2Cr2O7) is ________ amu.
A) 107.09
B) 255.08
C) 242.18
D) 294.18
E) 333.08

The formula weight of silver chromate (Ag2CrO4) is ________ amu.
A) 159.87
B) 223.87
C) 331.73
D) 339.86
E) 175.87

The formula weight of ammonium sulfate ((NH4)2SO4), rounded to the nearest integer, is ________ amu.
A) 100
B) 118
C) 116
D) 132
E) 264

The molecular weight of the acetic acid (CH3CO2H), rounded to the nearest integer, is ________ amu.
A) 60
B) 48
C) 44
D) 32

The formula weight of a substance is ________.
A) identical to the molar mass
B) the same as the percent by mass weight
C) determined by combustion analysis
D) the sum of the atomic weights of each atom in its chemical formula
E) the weight of a sample of the substance

The formula weight of calcium nitrate (Ca(NO3)2), rounded to one decimal place, is ________ amu.
A) 102.1
B) 164.0
C) 204.2
D) 150.1
E) 116.1

What is the formula weight of magnesium fluoride (MgF2)?
A) 86.6
B) 43.3
C) 62.3
D) 67.6
E) 92.9

What is the formula weight of lead iodide (PbI2)?
A) 334.1
B) 168.7
C) 295.6
D) 461.0
E) 668.2

The mass % of C in methane (CH4) is ________.
A) 25.13
B) 133.6
C) 74.87
D) 92.26
E) 7.743

The mass % of H in methane (CH4) is ________.
A) 25.13
B) 4.032
C) 74.87
D) 92.26
E) 7.743

The mass % of F in the binary compound KrF2 is ________.
A) 18.48
B) 45.38
C) 68.80
D) 81.52
E) 31.20

Calculate the percentage by mass of nitrogen in PtCl2(NH3)2.
A) 4.67
B) 9.34
C) 9.90
D) 4.95
E) 12.67

Calculate the percentage by mass of lead in Pb(NO3)2.
A) 38.6
B) 44.5
C) 62.6
D) 65.3
E) 71.2

Calculate the percentage by mass of carbon in CO2.
A) 27.29
B) 75.10
C) 73.05
D) 72.71
E) 37.53

Calculate the percentage by mass of oxygen in Pb(NO3)2.
A) 9.7
B) 14.5
C) 19.3
D) 29.0
E) 33.4

Calculate the percentage by mass of ammonia in cisplatin, PtCl2(NH3)2.
A) 5.68
B) 11.35
C) 4.67
D) 12.53
E) 18.09

Calculate the percentage by mass of hydrogen in PtCl2(NH3)2.
A) 1.558
B) 1.008
C) 0.672
D) 0.034
E) 2.016

Which of the following contains the largest number of atoms in mole?
A) S8
B) C4H10
C) Al2(SO4)3
D) Na3PO4
E) Cl2

One mole of ________ contains the smallest number of atoms.
A) S8
B) C10H8
C) Al2(SO4)3
D) Na3PO4
E) NaCl

One million argon atoms is ________ mol (rounded to two significant figures) of argon atoms.
A) 3.0
B) 1.7 × 10^-18
C) 6.0 × 10²³
D) 1.0 × 10^-6
E) 1.0 × 10⁺⁶

How many molecules of CH4 are in 48.2 g of this compound?
A) 5.00 × 10^-24
B) 2.00 × 10²³
C) 4.64 × 10²⁶
D) 1.81 × 10²⁴
E) 4.00

A 30.5 gram sample of glucose (C6H12O6) contains ________ mol of glucose.
A) 0.424
B) 0.169
C) 5.90
D) 2.36
E) 0.136

A sample of CH2F2 with a mass of 19 g contains ________ atoms of F.
A) 2.2 × 10²³
B) 38
C) 3.3 × 10²⁴
D) 4.4 × 10²³
E) 9.5

A sample of CH4O with a mass of 32.0 g contains ________ molecules of CH4O.
A) 5.32 × 10^-23
B) 1.00
C) 1.88 × 10²²
D) 6.02 × 10²³
E) 32.0

How many atoms of nitrogen are in 10 g of NH4NO3?
A) 3.5
B) 1.5 × 10²³
C) 3.0 × 10²³
D) 1.8
E) 2

Gaseous neon has a density of 0.900 g/L at standard conditions. How many neon atoms are in 1.00 L of neon gas at standard conditions?
A) 5.42 × 10²³
B) 1.35 × 10²⁵
C) 7.41 × 10^-26
D) 2.69 × 10²²
E) 6.02 × 10²³

How many oxygen atoms are contained in 2.74 g of Al2(SO4)3?
A) 12
B) 6.02 × 10²³
C) 7.22 × 10²⁴
D) 5.79 × 10²²
E) 8.01 × 10^-3

What is the total number of atoms in 0.139 mol of Fe(OH₂)₆ ³⁺?
A) 19.0
B) 1.59 × 10²⁴
C) 8.37 × 102²
D) 2.64
E) 1.84 × 10²⁴

How many sulfur dioxide molecules are there in 1.80 mol of sulfur dioxide?
A) 1.08 × 10²³
B) 6.02 × 10²⁴
C) 1.80 × 10²⁴
D) 1.08 × 10²⁴
E) 6.02 × 10²³

How many sulfur dioxide molecules are there in 0.180 mol of sulfur dioxide?
A) 1.80 × 10²³
B) 6.02 × 10²⁴
C) 6.02 × 10²³
D) 1.08 × 10²⁴
E) 1.08 × 10²³

How many carbon atoms are there in 52.06 g of carbon dioxide?
A) 5.206 × 10²⁴
B) 3.134 × 10²⁵
C) 7.122 × 10²³
D) 8.648 × 10^-23
E) 1.424 × 10²⁴

How many oxygen atoms are there in 52.06 g of carbon dioxide?
A) 1.424 × 10²⁴
B) 6.022 × 10²³
C) 7.122 × 10²³
D) 5.088 × 10²³
E) 1.018 × 10²⁴

How many moles of sodium carbonate contain 1.773 × 10¹⁷ carbon atoms?
A) 5.890 × 10^-7
B) 2.945 × 10^-7
C) 1.473 × 10^-7
D) 8.836 × 10-⁷
E) 9.817 × 10^-8

How many grams of sodium carbonate contain 1.773 × 10¹⁷ carbon atoms?
A) 3.121 × 10^-5
B) 1.011 × 10^-5
C) 1.517 × 10^-5
D) 9.100 × 10^-5
E) 6.066 × 10^-5

The compound responsible for the characteristic smell of garlic is allicin, C6H10OS2. What is the mass (g) of 1.00 mol of allicin?
A) 34
B) 162
C) 86
D) 61
E) 19

The molecular formula of aspartame, the generic name of NutraSweet®, is C14H18N2O5. What is the mass (g) of 1.00 mol of aspartame?
A) 24
B) 156
C) 294
D) 43
E) 39

There are ________ oxygen atoms in 30 molecules of C20H42S3O2.
A) 6.0 × 10²³
B) 1.8 × 10²⁵
C) 3.6 × 10²⁵
D) 1.2 × 10²⁴
E) 60

A nitrogen oxide is 63.65% by mass nitrogen. The molecular formula could be ________.
A) NO
B) NO2
C) N2O
D) N2O4
E) either NO2 or N2O4

A sulfur oxide is 50.0% by mass sulfur. This molecular formula could be ________.
A) SO
B) SO2
C) S2O
D) S2O4
E) either SO2 or S2O4

Which hydrocarbon pair below has identical mass percentage of C?
A) C3H4 and C3H6
B) C2H4 and C3H4
C) C2H4 and C4H2
D) C2H4 and C3H6
E) none of the above

Propane (C3H8) reacts with oxygen in the air to produce carbon dioxide and water. In a particular experiment, 38.0 grams of carbon dioxide are produced from the reaction of 22.05 grams of propane with excess oxygen. What is the % yield in this reaction?
A) 38.0
B) 57.6
C) 66.0
D) 86.4
E) 94.5

When the following equation is balanced, the coefficients are ________.

NH3 (g) + O2 (g) → NO2 (g) + H2O (g)

A) 1, 1, 1, 1
B) 4, 7, 4, 6
C) 2, 3, 2, 3
D) 1, 3, 1, 2
E) 4, 3, 4, 3
Answer: B

When the following equation is balanced, the coefficients are ________.

Al(NO3)3 + Na2S → Al2S3 + NaNO3

A) 2, 3, 1, 6
B) 2, 1, 3, 2
C) 1, 1, 1, 1
D) 4, 6, 3, 2
E) 2, 3, 2, 3

When the following equation is balanced, the coefficient of H2 is ________.

K (s) + H2O (l) → KOH (aq) + H2 (g)

A) 1
B) 2
C) 3
D) 4
E) 5

When the following equation is balanced, the coefficient of Al is ________.

Al (s) + H2O (l) → Al(OH (s) + H2 (g)

A) 1
B) 2
C) 3
D) 5
E) 4

When the following equation is balanced, the coefficient of H2O is ________.

Ca (s) + H2O (l) → Ca(OH)2 (aq) + H2 (g)

A) 1
B) 2
C) 3
D) 5
E) 4

When the following equation is balanced, the coefficient of Al2O3 is ________.

Al2O3 (s) + C (s) + Cl2 (g) → AlCl3 (s) + CO (g)

A) 1
B) 2
C) 3
D) 4
E) 5

When the following equation is balanced, the coefficient of H2S is ________.

FeCl3 (aq) + H2S (g) → Fe2S3 (s) + HCl (aq)

A) 1
B) 2
C) 3
D) 5
E) 4

When the following equation is balanced, the coefficient of HCl is ________.

CaCO3 (s) + HCl (aq) → CaCl2 (aq) + CO2 (g) + H2O (l)

A) 1
B) 2
C) 3
D) 4
E) 0

When the following equation is balanced, the coefficient of HNO3 is ________.

HNO3 (aq) + CaCO3 (s) → Ca(NO3)2 (aq) + CO2 (g) + H2O (l)

A) 1
B) 2
C) 3
D) 5
E) 4

When the following equation is balanced, the coefficient of H3PO4 is ________.

H3PO4 (aq) + NaOH (aq) → Na3PO4 (aq) + H2O (l)

A) 1
B) 2
C) 3
D) 4
E) 0

When the following equation is balanced, the coefficient of C3H8O3 is ________.

C3H8O3 (g) + O2 (g) → CO2 (g) + H2O (g)

A) 1
B) 2
C) 3
D) 7
E) 5

When the following equation is balanced, the coefficient of O2 is ________.

C2H4O (g) + O2 (g) → CO2 (g) + H2O (g)

A) 2
B) 3
C) 4
D) 5
E) 1

Balance the following reaction and determine the coefficient of H2O.

CO (g) + H2 (g) → H2O (g) + CH4 (g)

A) 1
B) 2
C) 3
D) 4
E) 0

When the following equation is balanced, the coefficient of H2SO4 is ________.

H2SO4 (aq) + NaOH (aq) → Na2SO4 (aq) + H2O (l)

A) 1
B) 2
C) 3
D) 4
E) 0.5

When the following equation is balanced, the coefficient of water is ________.

K (s) + H2O (l) → KOH (aq) + H2 (g)

A) 1
B) 2
C) 3
D) 4
E) 5

Balance the following reaction and determine the coefficient of potassium hydroxide.

K (s) + H2O (l) → KOH (aq) + H2 (g)

A) 1
B) 2
C) 3
D) 4
E) 5

When the following equation is balanced, the coefficient of oxygen is ________.

PbS (s) + O2 (g) → PbO (s) + SO2 (g)

A) 1
B) 3
C) 2
D) 4
E) 5

When the following equation is balanced, the coefficient of sulfur dioxide is ________.

PbS (s) + O2 (g) → PbO (s) + SO2 (g)

A) 5
B) 1
C) 3
D) 2
E) 4

When the following equation is balanced, the coefficient of dinitrogen pentoxide is ________.

N2O5 (g) + H2O (l) → HNO3 (aq)

A) 1
B) 2
C) 3
D) 4
E) 5

When the following equation is balanced, the coefficient of water is ________.

N2O5 (g) + H2O (l) → HNO3 (aq)

A) 5
B) 2
C) 3
D) 4
E) 1

Balance the following reaction and determine the coefficient of nitric acid.

N2O5 (g) + H2O (l) → HNO3 (aq)

A) 5
B) 2
C) 3
D) 4
E) 1

Write the balanced equation for the reaction that occurs when methanol, CH3OH (l), is burned in air. What is the coefficient of methanol in the balanced equation?
A) 1
B) 2
C) 3
D) 4
E) 3/2

Write the balanced equation for the reaction that occurs when butane undergoes combustion. What is the coefficient of oxygen in the balanced equation?
A) 10
B) 8
C) 13
D) 4
E) 13/2

What is the coefficient of O2 when the following equation is completed and balanced?

C4H8O2 + O2 → ________

A) 2
B) 3
C) 5
D) 6
E) 1

Predict the product in the combination reaction below.

Al (s) + N2 (g) → ________

A) AlN
B) Al3N
C) AlN2
D) Al3N2
E) AlN3

The balanced equation for the decomposition of sodium azide is ________.
A) 2NaN3 (s) → 2Na (s) + 3N2 (g)
B) 2NaN3 (s) → Na2 (s) + 3N2 (g)
C) NaN3 (s) → Na (s) + N2 (g)
D) NaN3 (s) → Na (s) + N2 (g) + N (g)
E) 2NaN3 (s) → 2Na (s) + 2N2 (g)

There are ________ mol of carbon atoms in 4 mol of C4H8O2.
A) 4
B) 8
C) 16
D) 20
E) 32

There are ________ sulfur atoms in 25 molecules of C4H4S2.
A) 1.5 × 10²⁵
B) 4.8 × 10²⁵
C) 3.0 × 10²⁵
D) 50
E) 6.02 × 10²³

There are ________ hydrogen atoms in 25 molecules of C4H4S2.
A) 25
B) 3.8 × 10²⁴
C) 6.0 × 10²⁵
D) 100
E) 1.5 × 10²⁵

A sample of C3H8O that contains 200 molecules contains ________ carbon atoms.
A) 600
B) 200
C) 3.61 × 10²⁶
D) 1.20 × 10²⁶
E) 4.01 × 10²⁵

How many moles of carbon monoxide are there in 36.55 g of carbon monoxide?
A) 1.023
B) 1.305
C) 0.8307
D) 0.7761
E) 1023

How many moles of carbon dioxide are there in 52.06 g of carbon dioxide?
A) 0.8452
B) 1.183
C) 6.022 × 10²³
D) 8.648 × 10²³
E) 3.134 × 10²⁵

There are ________ molecules of methane in 0.123 mol of methane (CH4).
A) 5
B) 2.46 × 10^-2
C) 2.04 × 10^-25
D) 7.40 × 10²²
E) 0.615

What is the empirical formula of a compound that contains 27.0% S, 13.4% O, and 59.6% Cl by mass?
A) SOCl
B) SOCl2
C) S2OCl
D) SO2Cl
E) ClSO4

What is the empirical formula of a compound that contains 29% Na, 41% S, and 30% O by mass?
A) Na2S2O3
B) NaSO2
C) NaSO
D) NaSO3
E) Na2S2O6

What is the empirical formula of a compound that contains 49.4% K, 20.3% S, and 30.3% O by mass?
A) KSO2
B) KSO3
C) K2SO4
D) K2SO3
E) KSO4

A compound contains 40.0% C, 6.71% H, and 53.29% O by mass. The molecular weight of the compound is 60.05 amu. The molecular formula of this compound is ________.
A) C2H4O2
B) CH2O
C) C2H3O4
D) C2H2O4
E) CHO2

A compound that is composed of carbon, hydrogen, and oxygen contains 70.6% C, 5.9% H, and 23.5% O by mass. The molecular weight of the compound is 136 amu. What is the molecular formula?
A) C8H8O2
B) C8H4O
C) C4H4O
D) C9H12O
E) C5H6O2

A compound that is composed of only carbon and hydrogen contains 85.7% C and 14.3% H by mass. What is the empirical formula of the compound?
A) CH2
B) C2H4
C) CH4
D) C4H8
E) C86H14

A compound that is composed of only carbon and hydrogen contains 80.0% C and 20.0% H by mass. What is the empirical formula of the compound?
A) C20H60
B) C7H20
C) CH3
D) C2H6
E) CH4

A compound contains 38.7% K, 13.9% N, and 47.4% O by mass. What is the empirical formula of the compound?
A) KNO3
B) K2N2O3
C) KNO2
D) K2NO3
E) K4NO5

A 1.038 g sample of unknown containing C, H, and O yielded 2.48 g of CO2 and 0.510 g of H2O during combustion analysis. Determine the empirical formula of the compound.
A) C3H3O
B) C6H6O
C) CH3O
D) C6H6O2
E) C2H6O2

Combustion of a 1.031-g sample of a compound containing only carbon, hydrogen, and oxygen produced of CO2 and of H2O. What is the empirical formula of the compound?
A) C3H8O
B) C3H5O
C) C12H16O5
D) C3H9O3
E) C3H6O3

Combustion of a 0.9827-g sample of a compound containing only carbon, hydrogen, and oxygen produced 1.900 g of CO2 and 1.070 g of H2O. What is the empirical formula of the compound?
A) C2H5O
B) C5H7O3
C) C4H11O2
D) C4H10O
E) C2H5O2

The combustion of ammonia in the presence of excess oxygen yields NO2 and H2O:

4 NH3 (g) + 7 O2 (g) → 4 NO2 (g) + 6 H2O (g)

The combustion of 43.9 g of ammonia produces ________ g of NO2.
A) 2.58
B) 178
C) 119
D) 0.954
E) 43.9

The combustion of propane (C3H8) in the presence of excess oxygen yields CO2 and H2O:

C3H8 (g) + 5O2 (g) → 3CO2 (g) + 4H2O (g)

When 2.5 mol of O2 are consumed in their reaction, ________ mol of CO2 are produced.
A) 1.5
B) 3.0
C) 4.2
D) 7.5
E) 2.5

Calcium carbide (CaC2) reacts with water to produce acetylene (C2H2):

CaC2 (s) + 2H2O (g) → Ca(OH)2 (s) + C2H2 (g)

Production of 13 g of C2H2 requires consumption of ________ g of H2O.
A) 4.5
B) 9.0
C) 18
D) 4.8 × 10²
E) 4.8 × 10^-2

Calcium carbide (CaC2) reacts with water to produce acetylene (C2H2) as shown in the unbalanced reaction below:

CaC2 (s) + H2O (g) → Ca(OH)2 (s) + C2H2 (g)

How many grams of H2O are required to completely react with 82.4 g of CaC2.
A) 1.29
B) 11.6
C) 46.3
D) 23.2
E) 18.0

Under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield ammonia. Write the reaction and determine the mass of H2 (g) required to completely react with 25.8 g of N2.

A) 5.57
B) 1.86
C) 77.4
D) 2.78
E) 0.928

Under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield ammonia:

N2 (g) + 3H2 (g) → 2NH3 (g)

Determine the mass of N2 (g) required to completely react with 18.5 g of H2.
A) 0.51
B) 771
C) 257
D) 85.7
E) 6.17

Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide:

PbCO3 (s) → PbO (s) + CO2 (g)

How many grams of lead (II) oxide will be produced by the decomposition of 2.50 g of lead (II) carbonate?
A) 0.41
B) 2.50
C) 0.00936
D) 2.09
E) 2.61

The combustion of propane (C3H8) produces CO2 and H2O:

C3H8 (g) + 5O2 (g) → 3CO2 (g) + 4H2O (g)

The reaction of 2.5 mol of O2 with 4.6 mol of C3H8 will produce ________ mol of H2O.
A) 4.0
B) 1.25
C) 2.5
D) 2.0
E) 18.4

GeF3H is formed from GeH4 and GeF4 in the combination reaction:

GeH4 + 3GeF4 → 4GeF3H

If the reaction yield is 89.1%, how many moles of GeH4 are needed to produce 3.50 mol of GeF3H?
A) 15.7
B) 3.93
C) 0.982
D) 0.875
E) 2.95

Under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield ammonia:

N2 (g) + 3H2 (g) → 2NH3 (g)

If the reaction yield is 81.4 %, how many moles of N2 are needed to produce 8.50 mol of NH3?
A) 20.9
B) 10.4
C) 5.22
D) 6.92
E) 15.7

Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide:

PbCO3 (s) → PbO (s) + CO2 (g)

If the reaction yield is 92.4%, how many grams of lead (II) oxide will be produced by the decomposition of 1.30 g of lead (II) carbonate?
A) 1.00
B) 1.18
C) 1.20
D) 1.09
E) 1.41

The combustion of ammonia in the presence of oxygen yields NO2 and H2O:

4 NH3 (g) + 7 O2 (g) → 4 NO2 (g) + 6 H2O (g)

The combustion of 43.9 g of ammonia with 258 g of oxygen produces ________ g of NO2.
A) 212
B) 178
C) 119
D) 0.954
E) 43.9

What mass in grams of hydrogen is produced by the reaction of 31.3 g of magnesium with 2.12 g of water?

Mg (s) + 2H2O (l) → Mg(OH)2 (s) + H2 (g)

A) 0.119
B) 0.237
C) 0.474
D) 0.0593
E) 2.71

If the reaction yield is 88.2%, what mass in grams of hydrogen is produced by the reaction of 7.73 g of magnesium with 1.31 g of water?

Mg (s) + 2H2O (l) → Mg(OH)2 (s) + H2 (g)

A) 0.0646
B) 0.0323
C) 0.0733
D) 0.147
E) 0.641

Silver nitrate and aluminum chloride react with each other by exchanging anions:

3AgNO3 (aq) + AlCl3 (aq) → Al(NO3)3 (aq) + 3AgCl (s)

What mass in grams of AgCl is produced when 4.22 g of AgNO3 react with 7.73 g of AlCl3?
A) 2.76
B) 28.5
C) 24.9
D) 3.56
E) 11.9

How many moles of magnesium oxide are produced by the reaction of 1.82 g of magnesium nitride with of water?

Mg3N2 + 3H2O → 2NH3 + 3MgO

A) 0.0180
B) 0.0541
C) 0.00601
D) 0.984
E) 3.00

A 3.82-g sample of magnesium nitride is reacted with 7.73 g of water:
Mg3N2 + 3H2O → 2NH3 + 3MgO

The yield of MgO is 3.60 g. What is the percent yield in the reaction?
A) 94.5
B) 78.7
C) 46.6
D) 49.4
E) 20.8

Pentacarbonyliron (Fe(CO)5) reacts with phosphorous trifluoride (PF3) and hydrogen, releasing carbon monoxide:

Fe(CO)5 + PF3 + H2 → Fe(CO)2(PF3)2(H)2 + CO (not balanced)

The reaction of 9.0 mol of Fe(CO)5, 11.0 mol of PF3 and 3.0 mol of H2 will release ________ mol of CO.
A) 9
B) 3
C) 27
D) 16.5
E) 23

What is the maximum mass in grams of NH3 that can be produced by the reaction of of N2 with of H2 via the equation below?

N2 (g) + H2 (g) → NH3 (g) (not balanced)

A) 2.0
B) 1.2
C) 0.61
D) 17
E) 4.0

What is the maximum number of moles of SO3 that can be produced by the reaction of 2.0 mol of S with 3.0 mol of O2?

A) 2/3
B) 1.0
C) 5.0
D) 3.0
E) 2.0

Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide:

4Al (s) + 3O2 (g) → 2Al2O3 (s)

The maximum amount of Al2O3 that can be produced from 5.0 g of Al and 5.0 g of O2 is ________ g.
A) 19
B) 4.7
C) 9.4
D) 11
E) 2.5

Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride:

S (s) + 3F2(g) → SF6 (g)

The maximum amount of SF6 that can be produced from the reaction of 32.1 g of sulfur with 114G of fluorine is ________ g.
A) 584
B) 438
C) 146
D) 48.7
E) 219

Solid aluminum and gaseous oxygen react in a combination reaction to produce aluminum oxide:

4Al (s) + 3O2 (g) → 2Al2O3 (s)

In a particular experiment, the reaction of 2.5 g of Al with 2.5 g of O2 produced 3.5 g of Al2O3. The % yield of the reaction is ________.
A) 74
B) 37
C) 47
D) 66
E) 29

Sulfur and oxygen react in a combination reaction to produce sulfur trioxide, an environmental pollutant:

2S (s) + 3O2 (g) → 2SO3 (g)

In a particular experiment, the reaction of 1.0 g S with 1.0 g O2 produced 0.80 g of SO3. The % yield in this experiment is ________.
A) 32
B) 80
C) 21
D) 64
E) 47

Sulfur and fluorine react in a combination reaction to produce sulfur hexafluoride:

S (s) + 3F2 (g) → SF6 (g)

In a particular experiment, the percent yield is 83.1%. This means that in this experiment, a 4.50 g sample of fluorine yields ________ g of SF6 .
A) 9.58
B) 3.74
C) 4.79
D) 43.1
E) 14.4

When the following equation is balanced, the coefficients are ________.

C8H18+ O2 → CO2 + H2O

A) 4, 50, 16, 18
B) 1, 5, 2, 2
C) 2, 2, 7, 1
D) 1, 13, 8, 9
E) 2, 25, 16, 18

The formula weight of PbCO3 is ________ amu.
A) 279.2
B) 112.0
C) 118.0
D) 267.2
E) 235.2

The formula weight of Zn(ClO4)2 is ________ amu.
A) 164.7
B) 327.9
C) 228.6
D) 264.3
E) 116.7

The formula weight of LiClO4 is ________ amu.
A) 212.3
B) 101.0
C) 52.0
D) 106.3
E) 58.3

The molecular weight of 2-propanol ( C3H7OH ), known as rubbing alcohol, is ________ amu (rounded to one decimal place).
A) 59.1
B) 29.0
C) 60.1
D) 12.0
E) 34.0

The molecular weight of ethanol (C2H5OH), rounded to one decimal place, is ________ amu.
A) 45.1
B) 34.1
C) 29.1
D) 46.1
E) 29.0

The molecular weight of maltose ( C12H22O11 ), rounded to one decimal place, is ________ amu.
A) 507.2
B) 182.0
C) 45.0
D) 342.3
E) 29.0

What is the mass percent of C in carbonic acid (H2CO3).

What is the mass % of carbon in dimethylsulfoxide (C2H6SO) rounded to three significant figures?
A) 15.4
B) 19.7
C) 30.7
D) 7.74
E) 20.5

What is the mass % of oxygen in methanol?
A) 16.0
B) 12.0
C) 50.0
D) 4.00
E) 32.0

What is the mass % of aluminum in aluminum sulfate (Al2(SO4)3) rounded to three significant figures?
A) 7.90
B) 35.7
C) 15.8
D) 19.4
E) 342.2

What is the mass % of oxygen in lead (II) nitrate (Pb(NO3)2) rounded to three significant figures?
A) 4.83
B) 19.3
C) 29.0
D) 14.5
E) 0.331

There are ________ mol of carbon atoms in 5 mol of dimethylsulfoxide (C2H6SO).
A) 2
B) 5
C) 10
D) 12
E) 50

1 mole of which of the following will contain the largest number of atoms?
A) sodium
B) magnesium
C) mercury
D) neon
E) 1 mole of any element will contain the same number of atoms.

1 mole of which of the following will have the largest mass?
A) rubidium
B) magnesium
C) gold
D) neon
E) 1 mole of any element will contain the same mass.

How many grams of hydrogen are in 46 g of CH4O?
A) 5.8
B) 1.5
C) 2.8
D) 0.36
E) 180

There are ________ atoms of oxygen in 300 molecules of CH3CO2H.
A) 300
B) 600
C) 150
D) 3.6 × 10²⁶
E) 1.0 × 10^-22

How many grams of oxygen are in 56 g of C2H2O2?
A) 11
B) 58
C) 15
D) 31
E) 33

How many atoms of carbon are in 23.1 g of glucose (C6H12O6)?
A) 7.72 × 10²²
B) 4.63 × 10²³
C) 1.29 × 10²²
D) 6.00
E) 138.6

A 1.36-g sample of magnesium nitrate, Mg(NO3)2, contains ________ mol of this compound.
A) 109
B) 2.02
C) 0.0157
D) 0.0182
E) 0.00917

A 22.5-g sample of ammonium carbonate contains ________ mol of ammonium ions.
A) 0.467
B) 0.288
C) 0.234
D) 2.14
E) 3.47

What is the mass in grams of 9.76 × 10¹² atoms of naturally occurring potassium?
A) 2.41 × 10¹²
B) 2.50 × 10¹¹
C) 6.34 × 10^-10
D) 1.62 × 10^-11
E) 3.82 × 101⁴

What is the mass in grams of 2.00 × 10⁵ atoms of naturally occurring neon?
A) 6.08 × 10¹⁹
B) 2.43 × 10³⁰
C) 6.70 × 10^-18
D) 1.65 × 10^-20
E) 3.32 × 10^-24

How many moles of pyridine (C5H5N) are contained in 4.14 g of pyridine?
A) 0.0523
B) 327
C) 6.88 × 10^-24
D) 2.49 ×10²⁴
E) 79.1

How many moles of lithium phosphate (Li3PO4) are contained in 66.6 g of lithium phosphate?
A) 0.575
B) 7710
C) 1.11 × 10^-22
D) 4.01 × 10²⁵
E) 116

How many grams of calcium cyanide (Ca(CN)2) are contained in 0.69 mol of calcium cyanide?
A) 64
B) 0.0075
C) 1.2 × 10^-24
D) 4.2 × 10²³
E) 92

How many grams of phenol (C6H5OH) are contained in 5.50 mol of phenol?
A) 518
B) 0.0584
C) 9.14 × 10^-24
D) 3.31 × 10²⁴
E) 94.1

What is the empirical formula of a compound that is 66.6% C, 11.2% H, and 22.2% O by mass?
A) C4HO
B) C6HO2
C) C8H16O2
D) C6H11O
E) C4H8O

A certain alcohol contains only three elements, carbon, hydrogen, and oxygen. Combustion of a 60.00 gram sample of the alcohol produced 114.6 grams of CO2 and 70.44 grams of H2O. What is the empirical formula of the alcohol?

Lithium and nitrogen react to produce lithium nitride:

6Li (s) + N2 (g) → 2Li3N (s)

How many moles of N2 are needed to react with 0.550 mol of lithium?
A) 3.30
B) 0.550
C) 0.183
D) 1.65
E) 0.0917

The combustion of propane (C3H8) produces CO2 and H2O:

C3H8 (g) + 5O2 (g) → 3CO2 (g) + 4H2O (g)

The reaction of 2.5 mol of O2 will produce ________ mol of H2O.
A) 4.0
B) 3.0
C) 2.5
D) 2.0
E) 1.0

Magnesium and nitrogen react in a combination reaction to produce magnesium nitride:

3 Mg + N2 → Mg3N2

In a particular experiment, a 8.33-g sample of reacts completely. The mass of Mg consumed is ________ g.
A) 7.23
B) 21.7
C) 28.9
D) 0.92
E) 13.9

The combustion of ammonia in the presence of excess oxygen yields NO2 and H2O:

4 NH3 (g) + 7 O2 (g) → 4 NO2 (g) + 6 H2O (g)

The combustion of 14.4 g of ammonia consumes ________ g of oxygen.
A) 13.5
B) 28.8
C) 54.1
D) 47.3
E) 94.6

Lithium and nitrogen react to produce lithium nitride:

6Li (s) + N2 (g) → 2Li3N (s)

How many moles of lithium nitride are produced when 0.330 mol of lithium react in this fashion?
A) 0.110
B) 0.660
C) 0.0550
D) 0.990
E) 0.165

Lithium and nitrogen react in a combination reaction to produce lithium nitride:

6Li (s) + N2 (g) → 2Li3N (s)

How many moles of lithium are needed to produce 0.45 mol of Li3N when the reaction is carried out in the presence of excess nitrogen?
A) 0.23
B) 1.4
C) 0.15
D) 0.30
E) 2.7

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements:

2NaN3 (s) → 2Na (s) + 3N2 (g)

How many moles of N2 are produced by the decomposition of 1.75 mol of sodium azide?
A) 1.17
B) 5.25
C) 2.63
D) 0.583
E) 0.875

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements:

2NaN3 (s) → 2Na (s) + 3N2 (g)

How many grams of sodium azide are required to produce 28.0 g of nitrogen?
A) 1.50
B) 0.666
C) 65.0
D) 43.3
E) 97.5

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide:

2Mg (s) + O2(g) → 2MgO (s)

How many moles of O2 are consumed when 3.55 mol of magnesium burns?
A) 0.146
B) 0.563
C) 3.55
D) 7.10
E) 1.78

Calcium carbide (CaC2) reacts with water to produce acetylene (C2H2):

CaC2 (s) + 2H2O (g) → Ca(OH)2 (s) + C2H2 (g)

Production of 6.5 g of C2H2 requires consumption of ________ g of H2O.
A) 2.3
B) 4.5
C) 9.0
D) 480
E) 0.048

Lead (II) carbonate decomposes to give lead (II) oxide and carbon dioxide:

PbCO3 (s) → PbO (s) + CO2 (g)

________ grams of lead (II) oxide will be produced by the decomposition of 8.75 g of lead (II) carbonate?
A) 10.5
B) 2.50
C) 0.033
D) 7.31
E) 8.75

Lithium and nitrogen react in a combination reaction to produce lithium nitride:

6Li (s) + N2 (g) → 2Li3N (s)

In a particular experiment, 2.50-g samples of each reagent are reacted. The theoretical yield of lithium nitride is ________ g.
A) 2.51
B) 2.09
C) 12.5
D) 4.18
E) 6.2

Magnesium burns in air with a dazzling brilliance to produce magnesium oxide:

2Mg (s) + O2 (g) → 2MgO (s)

When 5.50 g of magnesium burns, the theoretical yield of magnesium oxide is ________ g.
A) 5.50
B) 9.12
C) 0.226
D) 4.56
E) 18.2

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide:

CaO (s) + H2O (l) → Ca(OH)2 (s)

A 3.50 g sample of CaO is reacted with 3.38 g of H2O. How many grams of water remain after completion of reaction?
A) 0.00
B) 0.00694
C) 2.25
D) 1.04
E) 0.125

If 588 grams of FeS2 is allowed to react with 352 grams of O2 according to the following unbalanced equation, how many grams of Fe2O3 are produced?

FeS2 + O2 → Fe2O3 + SO2

Calcium oxide reacts with water in a combination reaction to produce calcium hydroxide:

CaO (s) + H2O (l) → Ca(OH)2 (s)

In a particular experiment, a 2.00-g sample of CaO is reacted with excess water and 2.14 g of Ca(OH)2 is recovered. What is the percent yield in this experiment?
A) 107
B) 1.07
C) 2.88
D) 81.1
E) 93.3

Sulfur and oxygen react to produce sulfur trioxide. In a particular experiment, 7.9 grams of SO3 are produced by the reaction of 6.0 grams of O2 with 7.0 grams of S. What is the % yield of SO3 in this experiment?

S (s) + O2 (g) → SO3 (g) (not balanced)

A) 45
B) 53
C) 22.5
D) 79
E) 35

Complete and balance the following reaction, given that elemental sodium reacts with elemental oxygen to form Na2O (s).

K (s) + S (s) → ________

A compound was found to contain 90.6% lead (Pb) and 9.4% oxygen. The empirical formula for this compound is ________.

The combustion of propane (C3H8) in the presence of excess oxygen yields CO2 and H2O:

C3H8 (g) + 5O2 (g) → 3CO2 (g) + 4H2O (g)

How many grams of CO2 is produced when 12.5 g of C3H8 burns in open air?

Under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield ammonia. A 18.2 g sample of hydrogen requires ________ g of N2 for a complete reaction.

Water can be formed from the stoichiometric reaction of hydrogen with oxygen. How many grams of H2O is generated when 45.3 g of O2 reacts with excess hydrogen?

The combustion of carbon disulfide in the presence of excess oxygen yields carbon dioxide and sulfur dioxide. The combustion of 10 mol of CS2 in the presence of excess oxygen yields ________ mol of SO2.

The mass of a single atom of an element (in amu) is numerically equal to the mass in grams of that element.

The empirical weight is always a whole-number multiple of the molecular formula weight.

A great deal of oxygen is produced during combustion.

The quantity of product that is calculated to form when all of the limiting reagent reacts is called the percent yield.