Question 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?

Accepted Answer

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

Question 2

Lithium and nitrogen react to produce lithium nitride: 6Li (s)+ N2 (g)→ 2Li3N (s)
How many moles of N2 are needed to react with 0.710 mol of lithium?

Accepted Answer

A) 4.26 
B) 0.710 
C) 0.237 
D) 2.13 
E) 0.118

Question 3

There are ________ oxygen atoms in 30 molecules of C20H42S3O2.

Accepted Answer

A) 6.0 x 1023 
B) 1.8 x 1025 
C) 3.6 x 1025 
D) 1.2 x 1024 
E) 60

Question 4

When the following equation is balanced, the coefficients are __________. NH3 (g)+ O2 (g)→ NO2 (g)+ H2O (g)

Accepted Answer

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

Question 5

When the following equation is balanced, the coefficient of H2S is __________. FeCl3 (aq)+ H2S (g)→ Fe2S3 (s)+ HCl (aq)

Accepted Answer

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

Question 6

What is the maximum amount in grams of SO3 that can be produced by the reaction of 1.0 g of S with 1.0 g of O2 via the equation below? S (s)+ O2 (g)→ SO3 (g)(not balanced)

Accepted Answer

A) 0.27 
B) 1.7 
C) 2.5 
D) 3.8 
E) 2.0

Question 7

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

Accepted Answer

A) 23.63 
B) 11.82 
C) 25.05 
D) 12.53 
E) 18.09

Question 8

Of the reactions below, which one is a decomposition reaction?

Accepted Answer

A) NH4Cl → NH3 + HCl 
B) 2Mg + O2 → 2MgO 
C) 2N2 + 3 H2 → 2NH3 
D) 2CH4 + 4O2 → 2CO2 + 4H2O 
E) Cd(NO3)O2 + Na2S → CdS + 2NaNO3

Question 9

One mole of __________ contains the largest number of atoms.

Accepted Answer

A) S8 
B) C10H8 
C) Al2(SO4)3 
D) Na3PO4 
E) Cl2

Question 10

Under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield ammonia: N2 (g)+ 3 H2 (g)→ 2NH3 (g)
A __________ g sample of N2 requires 3.0 g of H2 for complete reaction.

Accepted Answer

A) 0.51 
B) 0.76 
C) 1.2 
D) 14.0 
E) 17.2

Question 11

A compound is composed of only C, H, and O. The combustion of a 0.519-g sample of the compound yields 1.24 g of CO2 and 0.255 g of H2O. What is the empirical formula of the compound?

Accepted Answer

A) C6H6O 
B) C3H3O 
C) CH3O 
D) C2H6O5 
E) C2H6O2

Question 12

How many moles of carbon dioxide are there in 52.06 g of carbon dioxide?

Accepted Answer

A) 0.8452 
B) 1.183 
C) 6.022 × 1023 
D) 8.648 × 1023 
E) 3.134 × 1025

Question 13

How many atoms of nitrogen are in 10 g of NH4NO3?

Accepted Answer

A) 3.5 
B) 1.5 × 1023 
C) 3.0 × 1023 
D) 1.8 
E) 2

Question 14

What is the empirical formula of a compound that contains 49.4% K, 20.3% S, and 30.3% O by mass?

Accepted Answer

A) KSO2 
B) KSO3 
C) K2SO4 
D) K2O3 
E) KSO4

Question 15

The combustion of propane (C₃H₈ )in the presence of excess oxygen yields CO₂ and H₂O: C₃H₈ (g)+ 5O₂ (g)→ 3CO₂ (g)+ 4 H₂O (g) When 7.3 g of C₃H₈ burns in the presence of excess O₂, __________ g of CO₂ is produced.

Accepted Answer

The answer of The combustion of propane (C₃H₈ )in the...

Question 16

How many grams of sodium carbonate contain 1.773 × 1017 carbon atoms?

Accepted Answer

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

Question 17

How many sulfur dioxide molecules are there in 1.80 mol of sulfur dioxide?

Accepted Answer

A) 1.08 × 1023 
B) 6.02 × 1024 
C) 1.80 × 1024 
D) 1.08 × 1024 
E) 6.02 × 1023

Question 18

Calculate the percentage by mass of lead in PbCO3.

Accepted Answer

A) 17.96 
B) 22.46 
C) 73.05 
D) 77.54 
E) 89.22

Question 19

There are __________ sulfur atoms in 25 molecules of C4H4S2.

Accepted Answer

A) 1.5 × 1025 
B) 4.8 × 1025 
C) 3.0 × 1025 
D) 50 
E) 6.02 × 1023

Question 20

How many moles of pyridine (C5H5N)are contained in 3.13 g of pyridine?

Accepted Answer

A) 0.0396 
B) 25.3 
C) 0.319 
D) 0.00404 
E) 4.04 × 103

Exam 3: Stoichiometry: Calculations With Chemical Formulas and Equations

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?

Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N₂ (g) → 2Li₃N (s) How many moles of N₂ are needed to react with 0.710 mol of lithium?

There are ________ oxygen atoms in 30 molecules of C₂₀H₄₂S₃O₂.

When the following equation is balanced, the coefficients are __________. NH₃ (g) + O₂ (g) → NO₂ (g) + H₂O (g)

When the following equation is balanced, the coefficient of H₂S is __________. FeCl₃ (aq) + H₂S (g) → Fe₂S₃ (s) + HCl (aq)

What is the maximum amount in grams of SO₃ that can be produced by the reaction of 1.0 g of S with 1.0 g of O₂ via the equation below? S (s) + O₂ (g) → SO₃ (g) (not balanced)

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

Of the reactions below, which one is a decomposition reaction?

One mole of __________ contains the largest number of atoms.

Under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield ammonia: N₂ (g) + 3 H₂ (g) → 2NH₃ (g) A __________ g sample of N₂ requires 3.0 g of H₂ for complete reaction.

A compound is composed of only C, H, and O. The combustion of a 0.519-g sample of the compound yields 1.24 g of CO₂ and 0.255 g of H₂O. What is the empirical formula of the compound?

How many moles of carbon dioxide are there in 52.06 g of carbon dioxide?

How many atoms of nitrogen are in 10 g of NH₄NO₃?

What is the empirical formula of a compound that contains 49.4% K, 20.3% S, and 30.3% O by mass?

The combustion of propane (C₃H₈ )in the presence of excess oxygen yields CO₂ and H₂O: C₃H₈ (g)+ 5O₂ (g)→ 3CO₂ (g)+ 4 H₂O (g) When 7.3 g of C₃H₈ burns in the presence of excess O₂, __________ g of CO₂ is produced.

How many grams of sodium carbonate contain 1.773 × 10¹⁷ carbon atoms?

How many sulfur dioxide molecules are there in 1.80 mol of sulfur dioxide?

Calculate the percentage by mass of lead in PbCO₃.

There are __________ sulfur atoms in 25 molecules of C₄H₄S₂.

How many moles of pyridine (C₅H₅N) are contained in 3.13 g of pyridine?

Exam 3: Stoichiometry: Calculations With Chemical Formulas and Equations

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?

Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N2 (g) → 2Li3N (s) How many moles of N2 are needed to react with 0.710 mol of lithium?

There are ________ oxygen atoms in 30 molecules of C20H42S3O2.

When the following equation is balanced, the coefficients are __________. NH3 (g) + O2 (g) → NO2 (g) + H2O (g)

When the following equation is balanced, the coefficient of H2S is __________. FeCl3 (aq) + H2S (g) → Fe2S3 (s) + HCl (aq)

What is the maximum amount in grams of SO3 that can be produced by the reaction of 1.0 g of S with 1.0 g of O2 via the equation below? S (s) + O2 (g) → SO3 (g) (not balanced)

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

Of the reactions below, which one is a decomposition reaction?

One mole of __________ contains the largest number of atoms.

Under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield ammonia: N2 (g) + 3 H2 (g) → 2NH3 (g) A __________ g sample of N2 requires 3.0 g of H2 for complete reaction.

A compound is composed of only C, H, and O. The combustion of a 0.519-g sample of the compound yields 1.24 g of CO2 and 0.255 g of H2O. What is the empirical formula of the compound?

How many moles of carbon dioxide are there in 52.06 g of carbon dioxide?

How many atoms of nitrogen are in 10 g of NH4NO3?

What is the empirical formula of a compound that contains 49.4% K, 20.3% S, and 30.3% O by mass?

The combustion of propane (C3H8 )in the presence of excess oxygen yields CO2 and H2O: C3H8 (g)+ 5O2 (g)→ 3CO2 (g)+ 4 H2O (g) When 7.3 g of C3H8 burns in the presence of excess O2, __________ g of CO2 is produced.

How many grams of sodium carbonate contain 1.773 × 1017 carbon atoms?

How many sulfur dioxide molecules are there in 1.80 mol of sulfur dioxide?

Calculate the percentage by mass of lead in PbCO3.

There are __________ sulfur atoms in 25 molecules of C4H4S2.

How many moles of pyridine (C5H5N) are contained in 3.13 g of pyridine?

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?

Lithium and nitrogen react to produce lithium nitride: 6Li (s) + N₂ (g) → 2Li₃N (s) How many moles of N₂ are needed to react with 0.710 mol of lithium?

There are ________ oxygen atoms in 30 molecules of C₂₀H₄₂S₃O₂.

When the following equation is balanced, the coefficients are __________. NH₃ (g) + O₂ (g) → NO₂ (g) + H₂O (g)

When the following equation is balanced, the coefficient of H₂S is __________. FeCl₃ (aq) + H₂S (g) → Fe₂S₃ (s) + HCl (aq)

What is the maximum amount in grams of SO₃ that can be produced by the reaction of 1.0 g of S with 1.0 g of O₂ via the equation below? S (s) + O₂ (g) → SO₃ (g) (not balanced)

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

Under appropriate conditions, nitrogen and hydrogen undergo a combination reaction to yield ammonia: N₂ (g) + 3 H₂ (g) → 2NH₃ (g) A __________ g sample of N₂ requires 3.0 g of H₂ for complete reaction.

A compound is composed of only C, H, and O. The combustion of a 0.519-g sample of the compound yields 1.24 g of CO₂ and 0.255 g of H₂O. What is the empirical formula of the compound?

How many atoms of nitrogen are in 10 g of NH₄NO₃?

The combustion of propane (C₃H₈ )in the presence of excess oxygen yields CO₂ and H₂O: C₃H₈ (g)+ 5O₂ (g)→ 3CO₂ (g)+ 4 H₂O (g) When 7.3 g of C₃H₈ burns in the presence of excess O₂, __________ g of CO₂ is produced.

How many grams of sodium carbonate contain 1.773 × 10¹⁷ carbon atoms?

Calculate the percentage by mass of lead in PbCO₃.

There are __________ sulfur atoms in 25 molecules of C₄H₄S₂.

How many moles of pyridine (C₅H₅N) are contained in 3.13 g of pyridine?