Question 1

Write a definition of the term molar mass.

Accepted Answer

The molar mass is th

Question 2

U.S. Lime & Minerals is a company that produces quicklime, CaO, by heating calcium hydroxide, Ca(OH)2. What is the percent yield if 45 grams of quicklime are obtained from 1 mole of calcium hydroxide?

Accepted Answer

A)  61% 
B)  80% 
C)  45% 
D)  100% 
E)  90% 
A)  61% 
B)  80% 
C)  45% 
D)  100% 
E)  90%

Question 3

Which statement about the following chemical reaction is not correct?
2H2 + O2 $\rightarrow$ 2H2O

Accepted Answer

A)  For every oxygen molecule consumed, two water molecules are produced. 
B)  For every two hydrogen molecules consumed, two water molecules are produced. 
C)  Two hydrogen molecules react with one oxygen molecule. 
D)  Four hydrogen molecules react with oxygen to produce two water molecules. 
E)  Four hydrogen atoms combine with two oxygen atoms to produce two water molecules. 
A)  For every oxygen molecule consumed, two water molecules are produced. 
B)  For every two hydrogen molecules consumed, two water molecules are produced. 
C)  Two hydrogen molecules react with one oxygen molecule. 
D)  Four hydrogen molecules react with oxygen to produce two water molecules. 
E)  Four hydrogen atoms combine with two oxygen atoms to produce two water molecules.

Question 4

Burning coal that contains sulfur releases sulfur dioxide gas into the atmosphere where it combines with water to form sulfurous and sulfuric acid, thereby producing acid rain. Assume sulfur in coal is in the form of pyrite (FeS2(s)), which reacts with molecular oxygen to produce Fe2O3(s) and SO2(g). Write the balanced equation for this reaction and report the sum of the stoichiometric coefficients, written as integers.

Accepted Answer

A)  16 
B)  14 
C)  23 
D)  25 
E)  18 
A)  16 
B)  14 
C)  23 
D)  25 
E)  18

Question 5

Which of the following contains the largest number of atoms?

Accepted Answer

A)  1 mol water 
B)  1 mol phosphorus trichloride 
C)  1 mol dinitrogen pentoxide 
D)  1 mol carbon dioxide 
E)  All of these contain the same number of atoms. 
A)  1 mol water 
B)  1 mol phosphorus trichloride 
C)  1 mol dinitrogen pentoxide 
D)  1 mol carbon dioxide 
E)  All of these contain the same number of atoms.

Question 6

As a purchasing agent for a pharmaceutical company, how much chlorine, Cl2, do you need to order to react completely with 500 kg of platinum, Pt, to make cisplatin, PtCl2(NH3)2?

Accepted Answer

A)  182 kg 
B)  500 kg 
C)  2,564 kg 
D)  364 kg 
E)  91 kg 
A)  182 kg 
B)  500 kg 
C)  2,564 kg 
D)  364 kg 
E)  91 kg

Question 7

Baking ammonia or ammonium bicarbonate (NH4HCO3, 79.1 g/mol) is a leavening agent used in some older recipes. As it is heated, it breaks down into three gases: ammonia, water, and carbon dioxide. For each 20 g of baking ammonia heated (about 4 tsp), how many grams of carbon dioxide are produced?

Accepted Answer

A)  15 g 
B)  7.5 g 
C)  11 g 
D)  22 g 
E)  20 g 
A)  15 g 
B)  7.5 g 
C)  11 g 
D)  22 g 
E)  20 g

Question 8

What is the molar mass of phosphorus pentachloride (PCl5)?

Accepted Answer

A)  177.25 g/mol 
B)  190.30 g/mol 
C)  208.22 g/mol 
D)  172.75 g/mol 
E)  202.82 g/mol 
A)  177.25 g/mol 
B)  190.30 g/mol 
C)  208.22 g/mol 
D)  172.75 g/mol 
E)  202.82 g/mol

Question 9

The acid-base reaction between phosphoric acid, H3PO4, and calcium hydroxide, Ca(OH)2, yields water and calcium phosphate. For each mole of calcium phosphate produced by this reaction, how many moles of water are produced?

Accepted Answer

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

Question 10

Sulfur dioxide from coal-fired power plants combines with water in the atmosphere to produce acid rain. What is the product when one molecule of SO2 reacts with one molecule of water?

Accepted Answer

A)  two molecules of sulfurous acid 
B)  one sulfate ion 
C)  two sulfite ions 
D)  one molecule of sulfuric acid 
E)  one molecule of sulfurous acid 
A)  two molecules of sulfurous acid 
B)  one sulfate ion 
C)  two sulfite ions 
D)  one molecule of sulfuric acid 
E)  one molecule of sulfurous acid

Question 11

A tiny speck (8.3*10-7 mol) of radioactive americium-241 is used in smoke detectors. How many atoms of americium-241 are there in one of these smoke detectors?

Accepted Answer

A)  5.0 * 1017 
B)  1.2 * 1020 
C)  2.9 * 1022 
D)  6.0 * 1023 
E)  8.3 * 107 
A)  5.0 * 1017 
B)  1.2 * 1020 
C)  2.9 * 1022 
D)  6.0 * 1023 
E)  8.3 * 107

Question 12

What mass of phosphoric acid (H3PO4, 98.00 g/mol) is produced from the reaction of 10.00 g of P4O10 (283.89 g/mol) with 12.00 g water?

Accepted Answer

A)  10.90 g 
B)  0.14 g 
C)  43.52 g 
D)  13.81 g 
E)  14.52 g 
A)  10.90 g 
B)  0.14 g 
C)  43.52 g 
D)  13.81 g 
E)  14.52 g

Question 13

Mesitylene is a liquid hydrocarbon. If 0.115 g of this compound is burned in pure oxygen to give 0.3790 g CO2 and 0.1035 g H2O, what is the empirical formula of the compound?

Accepted Answer

Write a definition of the term molar mass.

U.S. Lime & Minerals is a company that produces quicklime, CaO, by heating calcium hydroxide, Ca(OH)₂. What is the percent yield if 45 grams of quicklime are obtained from 1 mole of calcium hydroxide?

Which statement about the following chemical reaction is not correct? 2H₂ + O₂ $\rightarrow$ 2H₂O

Which of the following contains the largest number of atoms?

As a purchasing agent for a pharmaceutical company, how much chlorine, Cl₂, do you need to order to react completely with 500 kg of platinum, Pt, to make cisplatin, PtCl₂(NH₃)₂?

Baking ammonia or ammonium bicarbonate (NH₄HCO₃, 79.1 g/mol) is a leavening agent used in some older recipes. As it is heated, it breaks down into three gases: ammonia, water, and carbon dioxide. For each 20 g of baking ammonia heated (about 4 tsp), how many grams of carbon dioxide are produced?

What is the molar mass of phosphorus pentachloride (PCl₅)?

The acid-base reaction between phosphoric acid, H₃PO₄, and calcium hydroxide, Ca(OH)₂, yields water and calcium phosphate. For each mole of calcium phosphate produced by this reaction, how many moles of water are produced?

Sulfur dioxide from coal-fired power plants combines with water in the atmosphere to produce acid rain. What is the product when one molecule of SO₂ reacts with one molecule of water?

A tiny speck (8.3*10^-⁷ mol) of radioactive americium-241 is used in smoke detectors. How many atoms of americium-241 are there in one of these smoke detectors?

What mass of phosphoric acid (H₃PO₄, 98.00 g/mol) is produced from the reaction of 10.00 g of P₄O₁₀ (283.89 g/mol) with 12.00 g water?

Mesitylene is a liquid hydrocarbon. If 0.115 g of this compound is burned in pure oxygen to give 0.3790 g CO₂ and 0.1035 g H₂O, what is the empirical formula of the compound?

Matter and Energy: The Origin of the Universe

Atoms, Ions, and Molecules: Matter Starts Here

Solution Chemistry: The Hydrosphere

Thermochemistry: Energy Changes in Reactions

Properties of Gases: the Air We Breathe

A Quantum Model of Atoms: Waves and Particles

Chemical Bonds: What Makes a Gas a Greenhouse Gas

Molecular Geometry: Shape Determines Function

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Structures and Applications

Organic Chemistry: Fuels, Pharmaceuticals, Materials, and Life

Chemical Kinetics: Reactions in the Air We Breathe

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acid-Base and Solubility Equilibria: Reactions in Soil and Water

Metal Ions: Colorful and Essential

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: the Quest for Clean Energy

Biochemistry: the Compounds of Life

Nuclear Chemistry: Applications to Energy and Medicine

Life and the Periodic Table

Filters

Exam 3: Stoichiometry: Mass, Formulas, and Reactions

Write a definition of the term molar mass.

U.S. Lime & Minerals is a company that produces quicklime, CaO, by heating calcium hydroxide, Ca(OH)2. What is the percent yield if 45 grams of quicklime are obtained from 1 mole of calcium hydroxide?

Which statement about the following chemical reaction is not correct? 2H2 + O2 →\rightarrow→ 2H2O

Which of the following contains the largest number of atoms?

As a purchasing agent for a pharmaceutical company, how much chlorine, Cl2, do you need to order to react completely with 500 kg of platinum, Pt, to make cisplatin, PtCl2(NH3)2?

Baking ammonia or ammonium bicarbonate (NH4HCO3, 79.1 g/mol) is a leavening agent used in some older recipes. As it is heated, it breaks down into three gases: ammonia, water, and carbon dioxide. For each 20 g of baking ammonia heated (about 4 tsp), how many grams of carbon dioxide are produced?

What is the molar mass of phosphorus pentachloride (PCl5)?

The acid-base reaction between phosphoric acid, H3PO4, and calcium hydroxide, Ca(OH)2, yields water and calcium phosphate. For each mole of calcium phosphate produced by this reaction, how many moles of water are produced?

Sulfur dioxide from coal-fired power plants combines with water in the atmosphere to produce acid rain. What is the product when one molecule of SO2 reacts with one molecule of water?

A tiny speck (8.3*10-7 mol) of radioactive americium-241 is used in smoke detectors. How many atoms of americium-241 are there in one of these smoke detectors?

What mass of phosphoric acid (H3PO4, 98.00 g/mol) is produced from the reaction of 10.00 g of P4O10 (283.89 g/mol) with 12.00 g water?

Mesitylene is a liquid hydrocarbon. If 0.115 g of this compound is burned in pure oxygen to give 0.3790 g CO2 and 0.1035 g H2O, what is the empirical formula of the compound?

Matter and Energy: The Origin of the Universe

Atoms, Ions, and Molecules: Matter Starts Here

Solution Chemistry: The Hydrosphere

Thermochemistry: Energy Changes in Reactions

Properties of Gases: the Air We Breathe

A Quantum Model of Atoms: Waves and Particles

Chemical Bonds: What Makes a Gas a Greenhouse Gas

Molecular Geometry: Shape Determines Function

Intermolecular Forces: The Uniqueness of Water

Solutions: Properties and Behavior

Solids: Structures and Applications

Organic Chemistry: Fuels, Pharmaceuticals, Materials, and Life

Chemical Kinetics: Reactions in the Air We Breathe

Chemical Equilibrium: How Much Product Does a Reaction Really Make

Acid-Base and Solubility Equilibria: Reactions in Soil and Water

Metal Ions: Colorful and Essential

Thermodynamics: Spontaneous and Nonspontaneous Reactions and Processes

Electrochemistry: the Quest for Clean Energy

Biochemistry: the Compounds of Life

Nuclear Chemistry: Applications to Energy and Medicine

Life and the Periodic Table

Filters

U.S. Lime & Minerals is a company that produces quicklime, CaO, by heating calcium hydroxide, Ca(OH)₂. What is the percent yield if 45 grams of quicklime are obtained from 1 mole of calcium hydroxide?

Which statement about the following chemical reaction is not correct? 2H₂ + O₂ $\rightarrow$ 2H₂O

As a purchasing agent for a pharmaceutical company, how much chlorine, Cl₂, do you need to order to react completely with 500 kg of platinum, Pt, to make cisplatin, PtCl₂(NH₃)₂?

What is the molar mass of phosphorus pentachloride (PCl₅)?

The acid-base reaction between phosphoric acid, H₃PO₄, and calcium hydroxide, Ca(OH)₂, yields water and calcium phosphate. For each mole of calcium phosphate produced by this reaction, how many moles of water are produced?

Sulfur dioxide from coal-fired power plants combines with water in the atmosphere to produce acid rain. What is the product when one molecule of SO₂ reacts with one molecule of water?

A tiny speck (8.3*10^-⁷ mol) of radioactive americium-241 is used in smoke detectors. How many atoms of americium-241 are there in one of these smoke detectors?

What mass of phosphoric acid (H₃PO₄, 98.00 g/mol) is produced from the reaction of 10.00 g of P₄O₁₀ (283.89 g/mol) with 12.00 g water?

Mesitylene is a liquid hydrocarbon. If 0.115 g of this compound is burned in pure oxygen to give 0.3790 g CO₂ and 0.1035 g H₂O, what is the empirical formula of the compound?