Question 1

List three reasons why the actual yield for a chemical reaction may differ from the theoretical yield.

Accepted Answer

(1) The reactants and products reach an

Question 2

A restaurant owner went to clean his oven using a solution that contained 150 g of sodium hydroxide (NaOH, 40.0 g/mol). He decided to neutralize the excess solution with an amount of vinegar containing 300 g of acetic acid (CH3COOH, 60.1 g/mol). The products are sodium acetate (82.0 g/mol) and water (18.0 g/mol). Identify the excess reactant and the amount that remains unreacted. The neutralization reaction equation is
NaOH(aq) + CH3COOH(aq) $\rightarrow$NaOOCCH3(aq) + H2O(l)

Accepted Answer

A)  49.6 g of sodium hydroxide remain 
B)  74.6 g of sodium hydroxide remain 
C)  74.6 g of acetic acid remain 
D)  150 g of acetic acid remain 
E)  49.6 g of acetic acid remain 
A)  49.6 g of sodium hydroxide remain 
B)  74.6 g of sodium hydroxide remain 
C)  74.6 g of acetic acid remain 
D)  150 g of acetic acid remain 
E)  49.6 g of acetic acid remain

Question 3

In one analysis, 3.01 *1013 molecules of ozone were found in 1.00 mL of an air sample. How many moles of ozone is this?

Accepted Answer

A)  5.00 * 10-11 mol 
B)  1.81 * 1037 mol 
C)  1.81 *10-11 mol 
D)  5.00 * 1037 mol 
E)  6.02 *10-23 mol 
A)  5.00 * 10-11 mol 
B)  1.81 * 1037 mol 
C)  1.81 *10-11 mol 
D)  5.00 * 1037 mol 
E)  6.02 *10-23 mol

Question 4

What are the stoichiometric coefficients for oxygen and water, respectively, in the balanced chemical reaction equation representing the combustion of butane (C4H10)?

Accepted Answer

A)  4, 5 
B)  9, 5 
C)  13, 10 
D)  $\frac { 9 } { 2 }$
, 10 
E)  13, 5 
A)  4, 5 
B)  9, 5 
C)  13, 10 
D)  $\frac { 9 } { 2 }$
, 10 
E)  13, 5

Question 5

A hydrocarbon molecule contains carbon and hydrogen atoms in equal numbers. Its molar mass is 130.18 g/mol. What is the molecular formula for the hydrocarbon?

Accepted Answer

A)  C7H7 
B)  C12H12 
C)  C8H8 
D)  C10H10 
E)  CH 
A)  C7H7 
B)  C12H12 
C)  C8H8 
D)  C10H10 
E)  CH

Question 6

A quart of water has a mass of 0.948 kg. How many moles of water (18.02 g/mol) is this?

Accepted Answer

A)  0.0526 mol 
B)  52.6 mol 
C)  17.1 mol 
D)  17,100 mol 
E)  171 mol 
A)  0.0526 mol 
B)  52.6 mol 
C)  17.1 mol 
D)  17,100 mol 
E)  171 mol

Question 7

Write the balanced reaction equation for the decomposition of ammonium nitrate into nitrogen gas, oxygen gas, and water vapor.

Accepted Answer

2NH₄NO₃(s) @#LAT-DLM&

Question 8

One form of elemental sulfur is a ring of eight sulfur atoms. How many moles of molecular oxygen are consumed when one mole of this allotrope burns to make sulfur trioxide?

Accepted Answer

A)  3 
B)  6 
C)  12 
D)  18 
E)  24 
A)  3 
B)  6 
C)  12 
D)  18 
E)  24

Question 9

Calcium carbide, CaC2, reacts with water to produce acetylene gas, C2H2, which is used in welding applications. The other reaction product is calcium hydroxide, Ca(OH)2. How much calcium carbide is needed to produce 26 kg of acetylene, assuming the reaction yield is 100%?

Accepted Answer

Question 10

Water can be separated into its elements according to the following equation by electrolysis. If 20.0 g of water is decomposed by this method, how much oxygen gas is produced?
2H2O (l)$\rightarrow$2H2(g) + O2(g)

Accepted Answer

A)  17.8 g 
B)  8.9 g 
C)  35.6 g 
D)  16.0 g 
E)  10.0 g 
A)  17.8 g 
B)  8.9 g 
C)  35.6 g 
D)  16.0 g 
E)  10.0 g

Question 11

Elemental analysis of the soot produced by a candle flame shows that it is 7.75% H and 92.3% C by mass. What is the empirical formula of this hydrocarbon?

Accepted Answer

A)  CH 
B)  CH2 
C)  C2H 
D)  CH3 
E)  C2H3 
A)  CH 
B)  CH2 
C)  C2H 
D)  CH3 
E)  C2H3

Question 12

What mass of phosphoric acid (H3PO4, 98.0 g/mol) is produced from the reaction of 10.0 g of P4O10 (284 g/mol) with excess water?

Accepted Answer

A)  10.9 g 
B)  40.0 g 
C)  10.0 g 
D)  13.8 g 
E)  2.50 g 
A)  10.9 g 
B)  40.0 g 
C)  10.0 g 
D)  13.8 g 
E)  2.50 g

Question 13

For which of the following compounds are the empirical and molecular formulas the same?
Acetic acid, found in vinegar, CH3COOH
Formaldehyde, used to preserve biological specimens, CH2O
Ethanol, found in beer and wine, CH3CH2OH

Accepted Answer

Formaldehy

Question 14

Which statement about a balanced chemical reaction equation is always correct?

Accepted Answer

A)  The total number of moles of the products equals the total number of moles of the reactants. 
B)  The number of atoms of each kind is the same for the products as for the reactants. 
C)  The sum of the stoichiometric coefficients for the products equals the sum of the stoichiometric coefficients for the reactants. 
D)  The sum of the masses of gaseous reactants equals the sum of the masses of gaseous products. 
E)  The sum of the masses of solid products equals the sum of the masses of solid reactants. 
A)  The total number of moles of the products equals the total number of moles of the reactants. 
B)  The number of atoms of each kind is the same for the products as for the reactants. 
C)  The sum of the stoichiometric coefficients for the products equals the sum of the stoichiometric coefficients for the reactants. 
D)  The sum of the masses of gaseous reactants equals the sum of the masses of gaseous products. 
E)  The sum of the masses of solid products equals the sum of the masses of solid reactants.

Question 15

One form of asbestos called chrysotile is considered to be a human carcinogen. Mass analysis reveals that it has the empirical formula Mg3Si2H4O9. If the molar mass is 554 g/mol, which molecular formula is correct?

Accepted Answer

A)  MgSiO4(OH)2 
B)  Mg2Si4O8(OH)4 
C)  Mg3Si2O5(OH)4 
D)  Mg6Si4O10(OH)8 
E)  Mg9Si6O15(OH)12 
A)  MgSiO4(OH)2 
B)  Mg2Si4O8(OH)4 
C)  Mg3Si2O5(OH)4 
D)  Mg6Si4O10(OH)8 
E)  Mg9Si6O15(OH)12

Question 16

Which molecules shown below have the same mass percent composition?

Accepted Answer

A)  II, III, IV are the same. 
B)  Only II and III are the same. 
C)  Only I and III are the same. 
D)  I, II, and III are the same. 
E)  I & III are the same, and II & IV are the same. 
A)  II, III, IV are the same. 
B)  Only II and III are the same. 
C)  Only I and III are the same. 
D)  I, II, and III are the same. 
E)  I & III are the same, and II & IV are the same.

Question 17

Household bleach contains 5.0% sodium hypochlorite (NaOCl) by mass. Household ammonia contains 5.0% NH3 by mass. If 50.00 g of bleach are mixed with 50.00 g of 5.0% ammonia, what mass of the toxic chloramine gas would be produced by the following reaction?
NaOCl + NH3 $\rightarrow$ NH2Cl + NaOH

Accepted Answer

A)  5.0 g 
B)  2.5 g 
C)  1.7 g 
D)  7.6 g 
E)  3.2 g 
A)  5.0 g 
B)  2.5 g 
C)  1.7 g 
D)  7.6 g 
E)  3.2 g

Question 18

A gallon of water has a mass of 3.79 kg. How many moles of water (18.02 g/mol) is this?

Accepted Answer

A)  0.210 mol 
B)  210 mol 
C)  68.3 mol 
D)  68,300 mol 
E)  386 mol 
A)  0.210 mol 
B)  210 mol 
C)  68.3 mol 
D)  68,300 mol 
E)  386 mol

Question 19

An intermetallic titanium compound is used for medical implants and high quality jewelry. The composition of this compound is 70.68% titanium, 19.92% aluminum, and 9.400% vanadium. The molar masses of these elements are 47.88, 26.98, and 50.94 g/mol, respectively. What is the empirical formula of this compound?

Accepted Answer

A)  Ti4AlV 
B)  Ti6Al2V 
C)  Ti6Al4V 
D)  Ti8Al4V 
E)  Ti10Al5V2 
A)  Ti4AlV 
B)  Ti6Al2V 
C)  Ti6Al4V 
D)  Ti8Al4V 
E)  Ti10Al5V2

Question 20

A mass of 11.60 g of phosphoric acid was produced from the reaction of 10.00 g of P4O10 with 12.00 g water. What was the percent yield for this reaction?

Accepted Answer

A)  78.62% 
B)  101.1% 
C)  92.70% 
D)  84.00% 
E)  52.70% 
A)  78.62% 
B)  101.1% 
C)  92.70% 
D)  84.00% 
E)  52.70%

List three reasons why the actual yield for a chemical reaction may differ from the theoretical yield.

In one analysis, 3.01 *10¹³ molecules of ozone were found in 1.00 mL of an air sample. How many moles of ozone is this?

What are the stoichiometric coefficients for oxygen and water, respectively, in the balanced chemical reaction equation representing the combustion of butane (C₄H₁₀)?

A hydrocarbon molecule contains carbon and hydrogen atoms in equal numbers. Its molar mass is 130.18 g/mol. What is the molecular formula for the hydrocarbon?

A quart of water has a mass of 0.948 kg. How many moles of water (18.02 g/mol) is this?

Write the balanced reaction equation for the decomposition of ammonium nitrate into nitrogen gas, oxygen gas, and water vapor.

One form of elemental sulfur is a ring of eight sulfur atoms. How many moles of molecular oxygen are consumed when one mole of this allotrope burns to make sulfur trioxide?

Calcium carbide, CaC₂, reacts with water to produce acetylene gas, C₂H₂, which is used in welding applications. The other reaction product is calcium hydroxide, Ca(OH)₂. How much calcium carbide is needed to produce 26 kg of acetylene, assuming the reaction yield is 100%?

Water can be separated into its elements according to the following equation by electrolysis. If 20.0 g of water is decomposed by this method, how much oxygen gas is produced? 2H₂O (l) $\rightarrow$ 2H₂(g) + O₂(g)

Elemental analysis of the soot produced by a candle flame shows that it is 7.75% H and 92.3% C by mass. What is the empirical formula of this hydrocarbon?

What mass of phosphoric acid (H₃PO₄, 98.0 g/mol) is produced from the reaction of 10.0 g of P₄O₁₀ (284 g/mol) with excess water?

For which of the following compounds are the empirical and molecular formulas the same? Acetic acid, found in vinegar, CH₃COOH Formaldehyde, used to preserve biological specimens, CH₂O Ethanol, found in beer and wine, CH₃CH₂OH

Which statement about a balanced chemical reaction equation is always correct?

One form of asbestos called chrysotile is considered to be a human carcinogen. Mass analysis reveals that it has the empirical formula Mg₃Si₂H₄O₉. If the molar mass is 554 g/mol, which molecular formula is correct?

Which molecules shown below have the same mass percent composition?

A gallon of water has a mass of 3.79 kg. How many moles of water (18.02 g/mol) is this?

A mass of 11.60 g of phosphoric acid was produced from the reaction of 10.00 g of P₄O₁₀ with 12.00 g water. What was the percent yield for this reaction?

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

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Exam 3: Stoichiometry: Mass, Formulas, and Reactions

List three reasons why the actual yield for a chemical reaction may differ from the theoretical yield.

In one analysis, 3.01 *1013 molecules of ozone were found in 1.00 mL of an air sample. How many moles of ozone is this?

What are the stoichiometric coefficients for oxygen and water, respectively, in the balanced chemical reaction equation representing the combustion of butane (C4H10)?

A hydrocarbon molecule contains carbon and hydrogen atoms in equal numbers. Its molar mass is 130.18 g/mol. What is the molecular formula for the hydrocarbon?

A quart of water has a mass of 0.948 kg. How many moles of water (18.02 g/mol) is this?

Write the balanced reaction equation for the decomposition of ammonium nitrate into nitrogen gas, oxygen gas, and water vapor.

One form of elemental sulfur is a ring of eight sulfur atoms. How many moles of molecular oxygen are consumed when one mole of this allotrope burns to make sulfur trioxide?

Calcium carbide, CaC2, reacts with water to produce acetylene gas, C2H2, which is used in welding applications. The other reaction product is calcium hydroxide, Ca(OH)2. How much calcium carbide is needed to produce 26 kg of acetylene, assuming the reaction yield is 100%?

Water can be separated into its elements according to the following equation by electrolysis. If 20.0 g of water is decomposed by this method, how much oxygen gas is produced? 2H2O (l) →\rightarrow→ 2H2(g) + O2(g)

Elemental analysis of the soot produced by a candle flame shows that it is 7.75% H and 92.3% C by mass. What is the empirical formula of this hydrocarbon?

What mass of phosphoric acid (H3PO4, 98.0 g/mol) is produced from the reaction of 10.0 g of P4O10 (284 g/mol) with excess water?

For which of the following compounds are the empirical and molecular formulas the same? Acetic acid, found in vinegar, CH3COOH Formaldehyde, used to preserve biological specimens, CH2O Ethanol, found in beer and wine, CH3CH2OH

Which statement about a balanced chemical reaction equation is always correct?

One form of asbestos called chrysotile is considered to be a human carcinogen. Mass analysis reveals that it has the empirical formula Mg3Si2H4O9. If the molar mass is 554 g/mol, which molecular formula is correct?

Which molecules shown below have the same mass percent composition?

Household bleach contains 5.0% sodium hypochlorite (NaOCl) by mass. Household ammonia contains 5.0% NH3 by mass. If 50.00 g of bleach are mixed with 50.00 g of 5.0% ammonia, what mass of the toxic chloramine gas would be produced by the following reaction? NaOCl + NH3 →\rightarrow→ NH2Cl + NaOH

A gallon of water has a mass of 3.79 kg. How many moles of water (18.02 g/mol) is this?

A mass of 11.60 g of phosphoric acid was produced from the reaction of 10.00 g of P4O10 with 12.00 g water. What was the percent yield for this reaction?

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

In one analysis, 3.01 *10¹³ molecules of ozone were found in 1.00 mL of an air sample. How many moles of ozone is this?

What are the stoichiometric coefficients for oxygen and water, respectively, in the balanced chemical reaction equation representing the combustion of butane (C₄H₁₀)?

Calcium carbide, CaC₂, reacts with water to produce acetylene gas, C₂H₂, which is used in welding applications. The other reaction product is calcium hydroxide, Ca(OH)₂. How much calcium carbide is needed to produce 26 kg of acetylene, assuming the reaction yield is 100%?

Water can be separated into its elements according to the following equation by electrolysis. If 20.0 g of water is decomposed by this method, how much oxygen gas is produced? 2H₂O (l) $\rightarrow$ 2H₂(g) + O₂(g)

What mass of phosphoric acid (H₃PO₄, 98.0 g/mol) is produced from the reaction of 10.0 g of P₄O₁₀ (284 g/mol) with excess water?

For which of the following compounds are the empirical and molecular formulas the same? Acetic acid, found in vinegar, CH₃COOH Formaldehyde, used to preserve biological specimens, CH₂O Ethanol, found in beer and wine, CH₃CH₂OH

One form of asbestos called chrysotile is considered to be a human carcinogen. Mass analysis reveals that it has the empirical formula Mg₃Si₂H₄O₉. If the molar mass is 554 g/mol, which molecular formula is correct?

A mass of 11.60 g of phosphoric acid was produced from the reaction of 10.00 g of P₄O₁₀ with 12.00 g water. What was the percent yield for this reaction?