Question 1

Which of the following is the correct representation for absorbance of a sample?

Accepted Answer

A)  A = -log T 
B)  A = log (-T) 
C)  A = 10T 
D)  A = 10-T 
E)  A = 10-1/T 
A)  A = -log T 
B)  A = log (-T) 
C)  A = 10T 
D)  A = 10-T 
E)  A = 10-1/T

Question 2

A 2.288 g sample of a hydrocarbon is burned in an excess of dioxygen,producing 6.277 g CO2 and 5.139 g H2O.What is the empirical formula of the hydrocarbon?

Accepted Answer

A)  CH4 
B)  CH2 
C)  C2H3 
D)  CH3 
E)  CH 
A)  CH4 
B)  CH2 
C)  C2H3 
D)  CH3 
E)  CH

Question 3

The numbers preceding the formulas in chemical equations are referred to as the _____ coefficients.

Accepted Answer

The answer of The numbers preceding the formulas in chemical...

Question 4

2 Al(s)+ 6 HCl(aq)→ 2 AlCl3(aq)+ 3 H2(g) According to the equation above,what mass of aluminum is needed to completely react with 2.98 mol of hydrochloric acid?

Accepted Answer

A)  241 g 
B)  36.3 g 
C)  26.8 g 
D)  2.98 g 
E)  80.4 g 
A)  241 g 
B)  36.3 g 
C)  26.8 g 
D)  2.98 g 
E)  80.4 g

Question 5

Aspirin (C9H8O4)is produced by the reaction of salicylic acid (M = 138.1 g/mol)and acetic anhydride (M = 102.1 g/mol). C7H6O3(s)+ C4H6O3(   )→ C9H8O4(s)+ C2H4O2(   )
If you react 2.00 g C7H6O3 with 1.60 g C4H6O3,what mass of aspirin (M = 180.2 g/mol)can theoretically be obtained?

Accepted Answer

A)  0.40 g 
B)  2.61 g 
C)  2.82 g 
D)  1.53 g 
E)  3.60 g 
A)  0.40 g 
B)  2.61 g 
C)  2.82 g 
D)  1.53 g 
E)  3.60 g

Question 6

Pure copper may be produced by the reaction of copper(I)sulfide with oxygen gas as follows: Cu2S(s)+ O2(g)→ 2Cu(s)+ SO2(g)
If the reaction of 0.760 kg of copper(I)sulfide with excess oxygen produces 0.310 kg of copper metal,what is the percent yield?

Accepted Answer

A)  102 % 
B)  39.9 % 
C)  40.8 % 
D)  204 % 
E)  51.1 % 
A)  102 % 
B)  39.9 % 
C)  40.8 % 
D)  204 % 
E)  51.1 %

Question 7

Sulfur trioxide (SO3)is produced from the oxidation of SO2 as follows: 2 SO2 + O2 → 2 SO3 A 23-g sample of SO2 gives 18 g of SO3.Calculate the percent yield of sulfur trioxide,SO3.

Accepted Answer

A)  10 % 
B)  63 % 
C)  15 % 
D)  29 % 
E)  100 % 
A)  10 % 
B)  63 % 
C)  15 % 
D)  29 % 
E)  100 %

Question 8

Sulfur hexafluoride is produced by reacting elemental sulfur with fluorine gas. S8(s)+ 24 F2(g)→ 8 SF6(g)
What is the percent yield if 18.3 g SF6 is isolated from the reaction of 10.0 g S8 and 30.0 g F2?

Accepted Answer

A)  40.2% 
B)  45.8% 
C)  47.6% 
D)  54.6% 
E)  61.0% 
A)  40.2% 
B)  45.8% 
C)  47.6% 
D)  54.6% 
E)  61.0%

Question 9

A mass of 0.4113 g of an unknown acid,HA,is titrated with sodium hydroxide,NaOH.If the acid reacts with 28.10 mL of 0.1055 M aqueous sodium hydroxide,what is the molar mass of the acid?

Accepted Answer

A)  2.965 × 10-3 g/mol 
B)  9.128 g/mol 
C)  138.7 g/mol 
D)  337.3 g/mol 
E)  820.7 g/mol 
A)  2.965 × 10-3 g/mol 
B)  9.128 g/mol 
C)  138.7 g/mol 
D)  337.3 g/mol 
E)  820.7 g/mol

Question 10

What mass of Na2CO3 is present in 0.700 L of a 0.396 M Na2CO3 solution?

Accepted Answer

A)  29.4 g 
B)  74.2 g 
C)  42.0 g 
D)  187 g 
E)  60.0 g 
A)  29.4 g 
B)  74.2 g 
C)  42.0 g 
D)  187 g 
E)  60.0 g

Question 11

Pure copper may be produced by the reaction of copper(I)sulfide with oxygen gas as follows: Cu2S(s)+ O2(g)→ 2Cu(s)+ SO2(g)
What mass of copper(I)sulfide is required in order to prepare 0.750 kg of copper metal?

Accepted Answer

A)  0.750 kg 
B)  0.375 kg 
C)  0.564 kg 
D)  1.88 kg 
E)  0.939 kg 
A)  0.750 kg 
B)  0.375 kg 
C)  0.564 kg 
D)  1.88 kg 
E)  0.939 kg

Question 12

What volume of 0.742 M Na2CO3 solution contains 44.9 g of Na2CO3?

Accepted Answer

A)  0.314 L 
B)  6.41 × 103 L 
C)  0.571 L 
D)  3.53 × 103 L 
E)  1.75 L 
A)  0.314 L 
B)  6.41 × 103 L 
C)  0.571 L 
D)  3.53 × 103 L 
E)  1.75 L

Question 13

If 15.0 g of nitrogen (N2)and 2.00 g of hydrogen (H2)react to produce 1.38 g of ammonia (NH3),according to the reaction below,what is the percent yield of the reaction? N2(g)+ 3 H2(g)→ 2 NH3(g)

Accepted Answer

A)  7.57% 
B)  12.2% 
C)  8.12% 
D)  15.1% 
E)  8.17% 
A)  7.57% 
B)  12.2% 
C)  8.12% 
D)  15.1% 
E)  8.17%

Question 14

Of the following,the only empirical formula is

Accepted Answer

A)  C6H12. 
B)  C4H8. 
C)  C3H14. 
D)  H2O2. 
E)  O3. 
A)  C6H12. 
B)  C4H8. 
C)  C3H14. 
D)  H2O2. 
E)  O3.

Question 15

A 5.95-g sample of AgNO3 is reacted with excess BaCl2 according to the equation 2AgNO3(aq)+ BaCl2(aq)→ 2AgCl(s)+ Ba(NO3)2(aq)
To give 3.57 g of AgCl.What is the percent yield of AgCl?

Accepted Answer

A)  47.4 % 
B)  35.6 % 
C)  71.1 % 
D)  60.0 % 
E)  100 % 
A)  47.4 % 
B)  35.6 % 
C)  71.1 % 
D)  60.0 % 
E)  100 %

Question 16

Nitric oxide,NO,is made from the oxidation of NH3 as follows: 4NH3 + 5O2 → 4NO + 6H2O If 9.0-g of NH3 gives 12.0 g of NO,what is the percent yield of NO?

Accepted Answer

A)  87 % 
B)  47 % 
C)  13 % 
D)  76 % 
E)  25 % 
A)  87 % 
B)  47 % 
C)  13 % 
D)  76 % 
E)  25 %

Question 17

Magnesium reacts with iodine gas at high temperatures to form magnesium iodide.What mass of magnesium iodide,MgI2,can be produced from the reaction of 5.15 g Mg and 50.0 g I2?

Accepted Answer

A)  29.5 g 
B)  44.9 g 
C)  54.8 g 
D)  55.2 g 
E)  58.9 g 
A)  29.5 g 
B)  44.9 g 
C)  54.8 g 
D)  55.2 g 
E)  58.9 g

Exam 5: Stoichiometry: Quantitative Information About Chemical Reactions

Which of the following is the correct representation for absorbance of a sample?

A 2.288 g sample of a hydrocarbon is burned in an excess of dioxygen,producing 6.277 g CO2 and 5.139 g H2O.What is the empirical formula of the hydrocarbon?

The numbers preceding the formulas in chemical equations are referred to as the _____ coefficients.

2 Al(s)+ 6 HCl(aq)→ 2 AlCl3(aq)+ 3 H2(g) According to the equation above,what mass of aluminum is needed to completely react with 2.98 mol of hydrochloric acid?

Aspirin (C9H8O4)is produced by the reaction of salicylic acid (M = 138.1 g/mol)and acetic anhydride (M = 102.1 g/mol). C7H6O3(s)+ C4H6O3( )→ C9H8O4(s)+ C2H4O2( ) If you react 2.00 g C7H6O3 with 1.60 g C4H6O3,what mass of aspirin (M = 180.2 g/mol)can theoretically be obtained?

Pure copper may be produced by the reaction of copper(I)sulfide with oxygen gas as follows: Cu2S(s)+ O2(g)→ 2Cu(s)+ SO2(g) If the reaction of 0.760 kg of copper(I)sulfide with excess oxygen produces 0.310 kg of copper metal,what is the percent yield?

Sulfur trioxide (SO3)is produced from the oxidation of SO2 as follows: 2 SO2 + O2 → 2 SO3 A 23-g sample of SO2 gives 18 g of SO3.Calculate the percent yield of sulfur trioxide,SO3.

Sulfur hexafluoride is produced by reacting elemental sulfur with fluorine gas. S8(s)+ 24 F2(g)→ 8 SF6(g) What is the percent yield if 18.3 g SF6 is isolated from the reaction of 10.0 g S8 and 30.0 g F2?

A mass of 0.4113 g of an unknown acid,HA,is titrated with sodium hydroxide,NaOH.If the acid reacts with 28.10 mL of 0.1055 M aqueous sodium hydroxide,what is the molar mass of the acid?

What mass of Na2CO3 is present in 0.700 L of a 0.396 M Na2CO3 solution?

Pure copper may be produced by the reaction of copper(I)sulfide with oxygen gas as follows: Cu2S(s)+ O2(g)→ 2Cu(s)+ SO2(g) What mass of copper(I)sulfide is required in order to prepare 0.750 kg of copper metal?

What volume of 0.742 M Na2CO3 solution contains 44.9 g of Na2CO3?

If 15.0 g of nitrogen (N2)and 2.00 g of hydrogen (H2)react to produce 1.38 g of ammonia (NH3),according to the reaction below,what is the percent yield of the reaction? N2(g)+ 3 H2(g)→ 2 NH3(g)

Of the following,the only empirical formula is

A 5.95-g sample of AgNO3 is reacted with excess BaCl2 according to the equation 2AgNO3(aq)+ BaCl2(aq)→ 2AgCl(s)+ Ba(NO3)2(aq) To give 3.57 g of AgCl.What is the percent yield of AgCl?

Nitric oxide,NO,is made from the oxidation of NH3 as follows: 4NH3 + 5O2 → 4NO + 6H2O If 9.0-g of NH3 gives 12.0 g of NO,what is the percent yield of NO?

Magnesium reacts with iodine gas at high temperatures to form magnesium iodide.What mass of magnesium iodide,MgI2,can be produced from the reaction of 5.15 g Mg and 50.0 g I2?

Basic Concepts of Chemistry

Lets Review: The Tools of Quantitative Chemistry

Atoms, molecules, and Ions

Chemical Reactions

Principles of Chemical Reactivity: Energy and Chemical Reactions

The Structure of Atoms

The Structure of Atoms and Periodic Trends

Bonding and Molecular Structure

Bonding and Molecular Structure Orbital Hybridization and Molecular Orbitals

Gases and Their Properties

Intermolecular Forces and Liquids

The Solid State

Solutions and Their Behavior

Chemical Kinetics: the Rates of Chemical Reactions

Principles of Chemical Reactivity: Equilibria

Principles of Chemical Reactivity: the Chemistry of Acids and Bases

Principles of Chemical Reactivity: Other Aspects of Aqueous Equilibria

Principles of Chemical Reactivity: Entropy and Free Energy

Principles of Chemical Reactivity: Electron Transfer Reactions

Environmental Chemistry: Earths Environment, energy, and Sustainability

The Chemistry of the Main Group Elements

The Chemistry of the Transition Elements

Carbon: Not Just Another Element

Biochemistry

Nuclear Chemistry

Filters

A 2.288 g sample of a hydrocarbon is burned in an excess of dioxygen,producing 6.277 g CO₂ and 5.139 g H₂O.What is the empirical formula of the hydrocarbon?

2 Al(s)+ 6 HCl(aq)→ 2 AlCl₃(aq)+ 3 H₂(g) According to the equation above,what mass of aluminum is needed to completely react with 2.98 mol of hydrochloric acid?

Pure copper may be produced by the reaction of copper(I)sulfide with oxygen gas as follows: Cu₂S(s)+ O₂(g)→ 2Cu(s)+ SO₂(g) If the reaction of 0.760 kg of copper(I)sulfide with excess oxygen produces 0.310 kg of copper metal,what is the percent yield?

Sulfur trioxide (SO₃)is produced from the oxidation of SO₂as follows: 2 SO₂ + O₂ → 2 SO₃ A 23-g sample of SO₂ gives 18 g of SO₃.Calculate the percent yield of sulfur trioxide,SO₃.

Sulfur hexafluoride is produced by reacting elemental sulfur with fluorine gas. S₈(s)+ 24 F₂(g)→ 8 SF₆(g) What is the percent yield if 18.3 g SF₆ is isolated from the reaction of 10.0 g S₈ and 30.0 g F₂?

What mass of Na₂CO₃ is present in 0.700 L of a 0.396 M Na₂CO₃ solution?

Pure copper may be produced by the reaction of copper(I)sulfide with oxygen gas as follows: Cu₂S(s)+ O₂(g)→ 2Cu(s)+ SO₂(g) What mass of copper(I)sulfide is required in order to prepare 0.750 kg of copper metal?

What volume of 0.742 M Na₂CO₃ solution contains 44.9 g of Na₂CO₃?

If 15.0 g of nitrogen (N₂)and 2.00 g of hydrogen (H₂)react to produce 1.38 g of ammonia (NH₃),according to the reaction below,what is the percent yield of the reaction? N₂(g)+ 3 H₂(g)→ 2 NH₃(g)

A 5.95-g sample of AgNO₃ is reacted with excess BaCl₂ according to the equation 2AgNO₃(aq)+ BaCl₂(aq)→ 2AgCl(s)+ Ba(NO₃)₂(aq) To give 3.57 g of AgCl.What is the percent yield of AgCl?

Nitric oxide,NO,is made from the oxidation of NH₃ as follows: 4NH₃ + 5O₂ → 4NO + 6H₂O If 9.0-g of NH₃ gives 12.0 g of NO,what is the percent yield of NO?

Magnesium reacts with iodine gas at high temperatures to form magnesium iodide.What mass of magnesium iodide,MgI₂,can be produced from the reaction of 5.15 g Mg and 50.0 g I₂?