Question 1

When the following equation is balanced, the coefficients are .

Accepted Answer

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

Question 2

The formula weight of potassium phosphate (K3PO4) is _ amu.

Accepted Answer

A)  212.27 
B)  86.07 
C)  251.37 
D)  173.17 
E)  196.27 
A)  212.27 
B)  86.07 
C)  251.37 
D)  173.17 
E)  196.27 A

Question 3

Lithium and nitrogen react in a combination reaction to produce lithium nitride:
 
How many moles of N2 are needed to react with 0.500 mol of lithium?

Accepted Answer

A)  1.50 
B)  0.0833 
C)  3.00 
D)  0.167 
E)  0.500 
A)  1.50 
B)  0.0833 
C)  3.00 
D)  0.167 
E)  0.500 B

Question 4

A sample of CH4O with a mass of 32.0 g contains molecules of CH4O.

Accepted Answer

A)  32.0 
B)  1.00 
C)  5.32 × 10- 23 
D)  1.88 × 1022 
E)  6.02 × 1023 
A)  32.0 
B)  1.00 
C)  5.32 × 10- 23 
D)  1.88 × 1022 
E)  6.02 × 1023

Question 5

How many oxygen atoms are there in 52.06 g of carbon dioxide?

Accepted Answer

A)  1.018 × 1024 
B)  1.424 × 1024 
C)  6.022 × 1023 
D)  5.088 × 1023 
E)  1.204 × 1024 
A)  1.018 × 1024 
B)  1.424 × 1024 
C)  6.022 × 1023 
D)  5.088 × 1023 
E)  1.204 × 1024

Question 6

The balanced equation for the decomposition of sodium azide is .

Accepted Answer

A)  2NaN3 (s) - 2Na (s) + 2N2 (g) 
B)  2NaN3 (s) -Na2 (s) + 3N2 (g) 
C)  NaN3 (s) - Na (s) + N2 (g) + N (g) 
D)  2NaN3 (s) - 2Na (s) + 3N2 (g) 
E)  NaN3 (s) - Na (s) + N2 (g) 
A)  2NaN3 (s) - 2Na (s) + 2N2 (g) 
B)  2NaN3 (s) -Na2 (s) + 3N2 (g) 
C)  NaN3 (s) - Na (s) + N2 (g) + N (g) 
D)  2NaN3 (s) - 2Na (s) + 3N2 (g) 
E)  NaN3 (s) - Na (s) + N2 (g)

Question 7

A 22.5- g sample of ammonium carbonate contains mol of ammonium ions.

Accepted Answer

A)  2.14 
B)  0.234 
C)  0.468 
D)  3.47 
E)  0.288 
A)  2.14 
B)  0.234 
C)  0.468 
D)  3.47 
E)  0.288

Question 8

Pentacarbonyliron (Fe(CO)5) reacts with phosphorous trifluoride (PF3) and hydrogen, releasing carbon monoxide:
 
The reaction of 5.0 mol of Fe(CO)5, 8.0 mol of PF3 and 6.0 mol of H2 will release _ _ mol of CO.

Accepted Answer

A)  24 
B)  12 
C)  6.0 
D)  15 
E)  5.0 
A)  24 
B)  12 
C)  6.0 
D)  15 
E)  5.0

Question 9

Calculate the percentage by mass of nitrogen in PtCl2(NH3)2.

Accepted Answer

A)  4.67 
B)  9.34 
C)  4.95 
D)  12.67 
E)  9.90 
A)  4.67 
B)  9.34 
C)  4.95 
D)  12.67 
E)  9.90

Question 10

There are hydrogen atoms in 25 molecules of C4H4S2.

Accepted Answer

A)  3.8 × 1024  
B)  6.0 × 1025  
C)  100 
D)  1.5 × 1025  
E)  25 
A)  3.8 × 1024  
B)  6.0 × 1025  
C)  100 
D)  1.5 × 1025  
E)  25

Question 11

How many moles of magnesium oxide are produced by the reaction of 3.82 g of magnesium nitride with 7.73 g of water?

Accepted Answer

A)  0.0378 
B)  0.113 
C)  0.429 
D)  4.57 
E)  0.0756 
A)  0.0378 
B)  0.113 
C)  0.429 
D)  4.57 
E)  0.0756

Question 12

A sample of CH2F2 with a mass of 19 g contains _ atoms of F.

Accepted Answer

A)  38 
B)  9.5 
C)  2.2 × 1023  
D)  4.4 × 1023  
E)  3.3 × 1024 
A)  38 
B)  9.5 
C)  2.2 × 1023  
D)  4.4 × 1023  
E)  3.3 × 1024

Question 13

There are _ mol of carbon atoms in 4 mol of dimethylsulfoxide (C2H6SO).

Accepted Answer

A)  2 
B)  8 
C)  4 
D)  6 
E)  3 
A)  2 
B)  8 
C)  4 
D)  6 
E)  3

Question 14

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

Accepted Answer

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

Question 15

The formula of nitrobenzene is C6H5NO2. The molecular weight of this compound is amu.

Accepted Answer

A)  109.10 
B)  43.03 
C)  123.11 
D)  107.11 
E)  3.06 
A)  109.10 
B)  43.03 
C)  123.11 
D)  107.11 
E)  3.06

Question 16

What is the coefficient of O2 when the following equation is completed and balanced?
C4H8O2 + O2 -

Accepted Answer

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

Question 17

Determine the mass percent (to the hundredth's place) of H in sodium bicarbonate (NaHCO3).

Accepted Answer

Question 18

If 294 grams of FeS2 is allowed to react with 176 grams of O2 according to the following equation, how many grams of Fe2O3 are produced?

Accepted Answer

Question 19

The mass % of Al in aluminum sulfate (Al2(SO4)3) is .

Accepted Answer

A)  45.70 
B)  21.93 
C)  35.94 
D)  7.886 
E)  15.77 
A)  45.70 
B)  21.93 
C)  35.94 
D)  7.886 
E)  15.77

Question 20

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements:
  How many grams of sodium azide are required to produce 18.0 g of nitrogen?

Accepted Answer

A)  62.7 
B)  0.964 
C)  0.428 
D)  41.8 
E)  27.9 
A)  62.7 
B)  0.964 
C)  0.428 
D)  41.8 
E)  27.9

Exam 3: Stoichiometry: Calculations With Chemical Formulas and Equations

When the following equation is balanced, the coefficients are .

The formula weight of potassium phosphate (K3PO4) is _ amu.

Lithium and nitrogen react in a combination reaction to produce lithium nitride: How many moles of N2 are needed to react with 0.500 mol of lithium?

A sample of CH4O with a mass of 32.0 g contains molecules of CH4O.

How many oxygen atoms are there in 52.06 g of carbon dioxide?

The balanced equation for the decomposition of sodium azide is .

A 22.5- g sample of ammonium carbonate contains mol of ammonium ions.

Pentacarbonyliron (Fe(CO)5) reacts with phosphorous trifluoride (PF3) and hydrogen, releasing carbon monoxide: The reaction of 5.0 mol of Fe(CO)5, 8.0 mol of PF3 and 6.0 mol of H2 will release _ _ mol of CO.

Calculate the percentage by mass of nitrogen in PtCl2(NH3)2.

There are hydrogen atoms in 25 molecules of C4H4S2.

How many moles of magnesium oxide are produced by the reaction of 3.82 g of magnesium nitride with 7.73 g of water?

A sample of CH2F2 with a mass of 19 g contains _ atoms of F.

There are _ mol of carbon atoms in 4 mol of dimethylsulfoxide (C2H6SO).

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

The formula of nitrobenzene is C6H5NO2. The molecular weight of this compound is amu.

What is the coefficient of O2 when the following equation is completed and balanced? C4H8O2 + O2 -

Determine the mass percent (to the hundredth's place) of H in sodium bicarbonate (NaHCO3).

If 294 grams of FeS2 is allowed to react with 176 grams of O2 according to the following equation, how many grams of Fe2O3 are produced?

The mass % of Al in aluminum sulfate (Al2(SO4)3) is .

Automotive air bags inflate when sodium azide decomposes explosively to its constituent elements: How many grams of sodium azide are required to produce 18.0 g of nitrogen?

Introduction: Matter and Measurement

Atoms, Molecules, and Ions

Aqueous Reactions and Solution Stoichiometry

Electronic Structure of Atoms

Periodic Properties of the Elements

Basic Concepts of Chemical Bonding

Gases

Intermolecular Forces, Liquids, and Solids

Modern Materials

Properties of Solutions

Chemical Kinetics

Chemical Equilibrium

Acid-Base Equilibria

Additional Aspects of Equilibria

Chemistry of the Environment

Chemical Thermodynamics

Electrochemistry

Nuclear Chemistry

Chemistry of the Nonmetals

Metals and Metallurgy

Chemistry of Coordination Compounds

The Chemistry of Life: Organic and Biological Chemistry

Filters

The formula weight of potassium phosphate (K₃PO₄) is _ amu.

Lithium and nitrogen react in a combination reaction to produce lithium nitride: How many moles of N₂are needed to react with 0.500 mol of lithium?

A sample of CH₄O with a mass of 32.0 g contains molecules of CH₄O.

Pentacarbonyliron (Fe(CO)₅) reacts with phosphorous trifluoride (PF₃) and hydrogen, releasing carbon monoxide: The reaction of 5.0 mol of Fe(CO)₅, 8.0 mol of PF₃and 6.0 mol of H₂will release _ _ mol of CO.

Calculate the percentage by mass of nitrogen in PtCl₂(NH₃)₂.

There are hydrogen atoms in 25 molecules of C₄H₄S₂.

A sample of CH₂F₂with a mass of 19 g contains _ atoms of F.

There are _ mol of carbon atoms in 4 mol of dimethylsulfoxide (C₂H₆SO).

When the following equation is balanced, the coefficient of H₂is _ .

The formula of nitrobenzene is C₆H₅NO₂. The molecular weight of this compound is amu.

What is the coefficient of O₂when the following equation is completed and balanced? C₄H₈O₂+ O₂-

Determine the mass percent (to the hundredth's place) of H in sodium bicarbonate (NaHCO₃).

If 294 grams of FeS₂is allowed to react with 176 grams of O₂according to the following equation, how many grams of Fe₂O₃are produced?

The mass % of Al in aluminum sulfate (Al₂(SO₄)₃) is .