Question 1

Which of the following has the greatest mass?

Accepted Answer

A) 1.55 × 1023 molecules of O2 
B) 4.00 g of O2 
C) 0.125 mol of O2 
D) All of these have the same mass. 
A) 1.55 × 1023 molecules of O2 
B) 4.00 g of O2 
C) 0.125 mol of O2 
D) All of these have the same mass.

Question 2

-Ethanol has the molecular formula C2H6O.Which ball and stick model shown above represents ethanol? [gray spheres = C,black spheres = O,unshaded spheres = H]

Accepted Answer

A) model a) 
B) model b) 
C) model c) 
D) model d) 
A) model a) 
B) model b) 
C) model c) 
D) model d)

Question 3

Strontium phosphate reacts with sulfuric acid to form strontium sulfate and phosphoric acid.What is the coefficient for sulfuric acid when the equation is balanced using the lowest whole-numbered coefficients?

Accepted Answer

A) 1 
B) 2 
C) 3 
D) none of these 
A) 1 
B) 2 
C) 3 
D) none of these

Question 4

Oxygen can be produced from the catalytic decomposition of KClO3 as shown in the balanced equation below.
2 KClO3 → 2 KCl + 3 O2
What is the percent yield if 3.20 grams of oxygen are formed from the reaction of 12.3 grams of KClO3?

Accepted Answer

Question 5

How many grams of calcium chloride are needed to produce 10.0 g of potassium chloride? CaCl2(aq)+ K2CO3(aq)→ 2 KCl(aq)+ CaCO3(aq)

Accepted Answer

A) 0.134 g 
B) 7.44 g 
C) 9.28 g 
D) 18.56 g 
A) 0.134 g 
B) 7.44 g 
C) 9.28 g 
D) 18.56 g

Question 6

How many moles are in 7.8 g of acetamide,CH3CONH2?

Accepted Answer

Question 7

The balanced equation for the decomposition of water is shown below.
2 H2O → 2 H2 + O2
If 0.72 g of water react completely in this reaction,what is the theoretical yield of H2?

Accepted Answer

Question 8

What is the balanced chemical equation for the reaction of element A (unshaded spheres)with element B (shaded spheres)as represented below?

Accepted Answer

A) A + B → AB 
B) A + 3B → 3AB 
C) A2 + B → AB 
D) A2 + 2B → 2AB 
A) A + B → AB 
B) A + 3B → 3AB 
C) A2 + B → AB 
D) A2 + 2B → 2AB

Question 9

How many anions are there in 4.50 g of MgBr2?

Accepted Answer

A) 1.47 × 1022 anions 
B) 2.94 × 1022 anions 
C) 2.46 × 1025 anions 
D) 4.93 × 1025 anions 
A) 1.47 × 1022 anions 
B) 2.94 × 1022 anions 
C) 2.46 × 1025 anions 
D) 4.93 × 1025 anions

Question 10

Which one of the following is not an empirical formula?

Accepted Answer

A) CHO 
B) CH2O 
C) C2H4O 
D) C2H2O4 
A) CHO 
B) CH2O 
C) C2H4O 
D) C2H2O4

Question 11

Identify one mole of a substance.

Accepted Answer

A) 32.0 grams of H2 
B) 52.0 grams of Cr 
C) 8.0 grams of LiH 
D) All of these 
A) 32.0 grams of H2 
B) 52.0 grams of Cr 
C) 8.0 grams of LiH 
D) All of these

Question 12

The following diagram represents the reaction of A (unshaded spheres)with B (shaded spheres).What is the balanced chemical equation for this reaction,and what is the limiting reactant?

Accepted Answer

A) A2 + 2B → 2AB;A2 is the limiting reactant. 
B) A2 + 2B → 2AB;B is the limiting reactant. 
C) 4A2 + 6B → 6AB;A2 is the limiting reactant. 
D) 4A2 + 6B → 6AB;B is the limiting reactant. 
A) A2 + 2B → 2AB;A2 is the limiting reactant. 
B) A2 + 2B → 2AB;B is the limiting reactant. 
C) 4A2 + 6B → 6AB;A2 is the limiting reactant. 
D) 4A2 + 6B → 6AB;B is the limiting reactant.

Question 13

How many cations are in 0.500 g of MgBr2?

Accepted Answer

A) 1.37 × 1021 anions 
B) 1.64 × 1021 anions 
C) 2.22 × 1026 anions 
D) 4.43 × 1026 anions 
A) 1.37 × 1021 anions 
B) 1.64 × 1021 anions 
C) 2.22 × 1026 anions 
D) 4.43 × 1026 anions

Question 14

5.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? 
N2(g)+ 3 H2(g)→ 2 NH3(g)

Accepted Answer

A) 2.8 grams of hydrogen are left over. 
B) Hydrogen is the excess reactant. 
C) Nitrogen is the limiting reactant. 
D) The theoretical yield of ammonia is 6.1 g. 
A) 2.8 grams of hydrogen are left over. 
B) Hydrogen is the excess reactant. 
C) Nitrogen is the limiting reactant. 
D) The theoretical yield of ammonia is 6.1 g.

Question 15

How many oxygen atoms are there in 6.00 g of sodium dichromate,Na2Cr2O7?

Accepted Answer

A) 0.160 oxygen atoms 
B) 1.97 × 1021 oxygen atoms 
C) 1.37 × 1022 oxygen atoms 
D) 9.65 × 1022 oxygen atoms 
A) 0.160 oxygen atoms 
B) 1.97 × 1021 oxygen atoms 
C) 1.37 × 1022 oxygen atoms 
D) 9.65 × 1022 oxygen atoms

Question 16

When carbon dioxide dissolves in water,H+ is formed,which makes the solution acidic,as shown in the balanced equation below.
CO2 + H2O → HCO3- + H+
What is the percent yield if 0.0088 g of CO2 reacts with 900 g of H2O to form 0.000108 g of H+?

Accepted Answer

Question 17

Isoeugenol is the compound which gives the characteristic odor to nutmeg and contains carbon,hydrogen,and oxygen.If a 0.500 g sample of isoeugenol is combusted it gives 1.341 g of CO2 and 0.329 g of H2O.Isoeugenol has a molecular weight of 164 g/mol.What is the molecular formula of isoeugenol?

Accepted Answer

A) C2HO 
B) C5H6O 
C) C8H4O4 
D) C10H12O2 
A) C2HO 
B) C5H6O 
C) C8H4O4 
D) C10H12O2

Question 18

Balance the chemical equation given below,and determine the number of grams of MgO are needed to produce 25.0 g of Fe2O3. ________ MgO(s)+ ________ Fe(s)→ ________ Fe2O3(s)+ ________ Mg(s)

Accepted Answer

A) 0.0528 g 
B) 2.10 g 
C) 6.31 g 
D) 18.9 g 
A) 0.0528 g 
B) 2.10 g 
C) 6.31 g 
D) 18.9 g

Question 19

Balance the chemical equation given below,and calculate the volume of nitrogen monoxide gas produced when 8.00 g of ammonia is reacted with 9.00 g of oxygen at 25°C? The density of nitrogen monoxide at 25°C is 1.23 g/L. ________ NH3(g)+ ________ O2(g)→ ________ NO(g)+ ________ H2O(l)

Accepted Answer

A) 5.49 L 
B) 8.31 L 
C) 11.5 L 
D) 17.3 L 
A) 5.49 L 
B) 8.31 L 
C) 11.5 L 
D) 17.3 L

Question 20

Balance the chemical equation given below,and determine the number of moles of iodine that reacts with 10.0 g of aluminum. ________ Al(s)+ ________ I2(s)→ ________ Al2I6(s)

Accepted Answer

A) 0.247 mol 
B) 0.556 mol 
C) 0.741 mol 
D) 1.11 mol 
A) 0.247 mol 
B) 0.556 mol 
C) 0.741 mol 
D) 1.11 mol

Exam 3: Mass Relationships in Chemical Reactions

Which of the following has the greatest mass?

-Ethanol has the molecular formula C2H6O.Which ball and stick model shown above represents ethanol? [gray spheres = C,black spheres = O,unshaded spheres = H]

Strontium phosphate reacts with sulfuric acid to form strontium sulfate and phosphoric acid.What is the coefficient for sulfuric acid when the equation is balanced using the lowest whole-numbered coefficients?

Oxygen can be produced from the catalytic decomposition of KClO3 as shown in the balanced equation below. 2 KClO3 → 2 KCl + 3 O2 What is the percent yield if 3.20 grams of oxygen are formed from the reaction of 12.3 grams of KClO3?

How many grams of calcium chloride are needed to produce 10.0 g of potassium chloride? CaCl2(aq)+ K2CO3(aq)→ 2 KCl(aq)+ CaCO3(aq)

How many moles are in 7.8 g of acetamide,CH3CONH2?

The balanced equation for the decomposition of water is shown below. 2 H2O → 2 H2 + O2 If 0.72 g of water react completely in this reaction,what is the theoretical yield of H2?

What is the balanced chemical equation for the reaction of element A (unshaded spheres)with element B (shaded spheres)as represented below?

How many anions are there in 4.50 g of MgBr2?

Which one of the following is not an empirical formula?

Identify one mole of a substance.

The following diagram represents the reaction of A (unshaded spheres)with B (shaded spheres).What is the balanced chemical equation for this reaction,and what is the limiting reactant?

How many cations are in 0.500 g of MgBr2?

5.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? N2(g)+ 3 H2(g)→ 2 NH3(g)

How many oxygen atoms are there in 6.00 g of sodium dichromate,Na2Cr2O7?

When carbon dioxide dissolves in water,H+ is formed,which makes the solution acidic,as shown in the balanced equation below. CO2 + H2O → HCO3- + H+ What is the percent yield if 0.0088 g of CO2 reacts with 900 g of H2O to form 0.000108 g of H+?

Isoeugenol is the compound which gives the characteristic odor to nutmeg and contains carbon,hydrogen,and oxygen.If a 0.500 g sample of isoeugenol is combusted it gives 1.341 g of CO2 and 0.329 g of H2O.Isoeugenol has a molecular weight of 164 g/mol.What is the molecular formula of isoeugenol?

Balance the chemical equation given below,and determine the number of grams of MgO are needed to produce 25.0 g of Fe2O3. ________ MgO(s)+ ________ Fe(s)→ ________ Fe2O3(s)+ ________ Mg(s)

Balance the chemical equation given below,and calculate the volume of nitrogen monoxide gas produced when 8.00 g of ammonia is reacted with 9.00 g of oxygen at 25°C? The density of nitrogen monoxide at 25°C is 1.23 g/L. ________ NH3(g)+ ________ O2(g)→ ________ NO(g)+ ________ H2O(l)

Balance the chemical equation given below,and determine the number of moles of iodine that reacts with 10.0 g of aluminum. ________ Al(s)+ ________ I2(s)→ ________ Al2I6(s)

Chemical Tools: Experimentation and Measurement

Atoms, molecules, and Ions

Reactions in Aqueous Solutions

Periodicity and the Electronic Structure of Atoms

Ionic Compounds: Periodic Trends and Bonding

Covalent Bonding and Electron-Dot Structures

Covalent Compounds: Bonding Theories and Molecular Structure

Thermochemistry: Chemical Energy

Gases: Their Properties and Behavior

Liquids, solids, and Phase Changes

Solutions and Their Properties

Chemical Kinetics

Chemical Equilibrium

Aqueous Equilibria: Acids and Bases

Applications of Aqueous Equilibria

Thermodynamics: Entropy, free Energy, and Equilibrium

Electrochemistry

Nuclear Chemistry

Transition Elements and Coordination Chemistry

Metals and Solid-State Materials

The Main-Group Elements

Connections to Organic and Biological Chemistry

Filters

-Ethanol has the molecular formula C₂H₆O.Which ball and stick model shown above represents ethanol? [gray spheres = C,black spheres = O,unshaded spheres = H]

Oxygen can be produced from the catalytic decomposition of KClO₃ as shown in the balanced equation below. 2 KClO₃ → 2 KCl + 3 O₂ What is the percent yield if 3.20 grams of oxygen are formed from the reaction of 12.3 grams of KClO₃?

How many grams of calcium chloride are needed to produce 10.0 g of potassium chloride? CaCl₂(aq)+ K₂CO₃(aq)→ 2 KCl(aq)+ CaCO₃(aq)

How many moles are in 7.8 g of acetamide,CH₃CONH₂?

The balanced equation for the decomposition of water is shown below. 2 H₂O → 2 H₂ + O₂ If 0.72 g of water react completely in this reaction,what is the theoretical yield of H₂?

How many anions are there in 4.50 g of MgBr₂?

How many cations are in 0.500 g of MgBr₂?

5.0 g of nitrogen is reacted with 5.0 g of hydrogen to produce ammonia according to the chemical equation shown below.Which one of the following statements is false? N₂(g)+ 3 H₂(g)→ 2 NH₃(g)

How many oxygen atoms are there in 6.00 g of sodium dichromate,Na₂Cr₂O₇?

When carbon dioxide dissolves in water,H⁺ is formed,which makes the solution acidic,as shown in the balanced equation below. CO₂ + H₂O → HCO₃^- + H⁺ What is the percent yield if 0.0088 g of CO₂ reacts with 900 g of H₂O to form 0.000108 g of H⁺?

Isoeugenol is the compound which gives the characteristic odor to nutmeg and contains carbon,hydrogen,and oxygen.If a 0.500 g sample of isoeugenol is combusted it gives 1.341 g of CO₂ and 0.329 g of H₂O.Isoeugenol has a molecular weight of 164 g/mol.What is the molecular formula of isoeugenol?

Balance the chemical equation given below,and determine the number of grams of MgO are needed to produce 25.0 g of Fe₂O₃. MgO(s)+ Fe(s)→ Fe₂O₃(s)+ Mg(s)

Balance the chemical equation given below,and calculate the volume of nitrogen monoxide gas produced when 8.00 g of ammonia is reacted with 9.00 g of oxygen at 25°C? The density of nitrogen monoxide at 25°C is 1.23 g/L. NH₃(g)+ O₂(g)→ NO(g)+ H₂O(l)

Balance the chemical equation given below,and determine the number of moles of iodine that reacts with 10.0 g of aluminum. Al(s)+ I₂(s)→ Al₂I₆(s)