Question 1

If the combustion of fossil fuels adds about 5 *10¹² kg of carbon to the atmosphere as CO₂ each year, how much oxygen is required to produce this amount of carbon dioxide?

Accepted Answer

The balanced chemical equation for the combustion of fossil fuels can be written as:
C + O2 → CO2
From the equation, we can see that 1 mole of carbon requires 1 mole of oxygen to produce 1 mole of carbon dioxide. The molar mass of carbon is 12 g/mol, and the given mass of carbon is 5x10^10 kg. Therefore, the number of moles of carbon present is:
5x10^10 kg / 12 g/mol = 4.17x10^12 mol
This means that 4.17x10^12 mol of oxygen is required to produce this amount of carbon dioxide. The molar mass of oxygen is 16 g/mol, so the mass of oxygen required is:
4.17x10^12 mol x 16 g/mol = 6.67x10^13 g = 6.67x10^10 kg
Rounded to one significant figure, this is about 1.3x10^11 kg, which corresponds to answer choice B.

Question 2

Fe₂O₃(s) and powdered aluminum can react with great output of heat to form molten iron and Al₂O₃. When this reaction equation is balanced, what are the stoichiometric coefficients in the following order: Fe₂O₃, Al, Fe, Al₂O₃?

Accepted Answer

The balanced chemical equation for the reaction between iron(III) oxide (Fe2O3) and aluminum (Al) to produce iron (Fe) and aluminum oxide (Al2O3) is: Fe2O3 + 2Al → 2Fe + Al2O3. This shows the stoichiometric coefficients are 1 for Fe2O3, 2 for Al, 2 for Fe, and 1 for Al2O3, corresponding to option C.

Question 3

In a demonstration of the complete combustion of propane (C₃H₈) with oxygen (O₂), several balloons were prepared with various proportions by volume of propane and oxygen. The loudest explosion occurred for the balloon with the correct stoichiometric proportions of the gases. Which balloon had the loudest explosion?

Accepted Answer

The answer of In a demonstration of the complete combustion...

Question 4

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

The answer of One form of elemental sulfur is a...

Question 5

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

Accepted Answer

The balanced chemical equation for the combustion of butane is:
2C4H10 + 13O2 → 8CO2 + 10H2O
Therefore, the stoichiometric coefficient for oxygen is 13 and for water is 10.

Question 6

Identify the set of stoichiometric coefficients that balance the reaction equation for the combustion of octane. C₈H₁₈ + O₂ $\rightarrow$ CO₂ + H₂O

Accepted Answer

The balanced equation is: 
2C8H18 + 25O2 -> 16CO2 + 18H2O  
Therefore, the answer is D with the stoichiometric coefficients of 2, 25, 16, 18.

Question 7

The average adult exhales about 1.0 kg of carbon dioxide each day. How much oxygen is needed in metabolizing glucose (C₆H₁₂O₆, 180 g/mol) to make that much carbon dioxide?

Accepted Answer

The balanced equation for the metabolism of glucose is: C6H12O6 + 6O2 → 6CO2 + 6H2O. The molar ratio of glucose to carbon dioxide is 1:6. Therefore, to exhale 1.0 kg (1000 g) of carbon dioxide, we need to consume 1000/6 = 166.67 g of oxygen. However, the question is asking for the amount of oxygen needed to produce the carbon dioxide from 1.0 kg of exhaled carbon dioxide. Using the same molar ratio, we can calculate that 1.0 kg of carbon dioxide is produced from the metabolism of 166.67 x 6 = <<1000/6*6=1000>>1000 g of glucose. Therefore, the answer is D) 730 g, which is half of 1000 g (since glucose has a molar mass of 180 g/mol, we need 1000/2 = 500 moles of glucose, which is equal to 500 x 180 = 90,000 g or 730 kg of oxygen).

Question 8

Diesel fuel for automobiles and trucks is a mixture of hydrocarbons that can be modeled by C₁₆H₃₄. Write the balanced reaction equation for the combustion of C₁₆H₃₄, and report the sum of the stoichiometric coefficients.

Accepted Answer

The balanced reaction equation for the combustion of C₁₆H₃₄ is: C₁₆H₃₄ + 193O2 → 116CO2 + 67H2O + 193SO2 The sum of the stoichiometric coefficients is 116 + 193 + 67 + 193 = 569, which is closest to answer choice E (117).

Question 9

Which statement, A-D, regarding photosynthesis is not correct? In the process of photosynthesis __________

Accepted Answer

All statements A through D are correct regarding photosynthesis. Photosynthesis converts light energy into chemical energy, produces oxygen, consumes atmospheric carbon dioxide, and generates glucose.

Question 10

Ozone (O₃) reacts with iodide (I^-) and water to form iodine (I₂), hydroxide (OH^-), and oxygen (O₂). What is the sum of the stoichiometric coefficients in the balanced reaction equation? O₃ + I^- + H₂O $\rightarrow$ I₂ + OH^- + O₂

Accepted Answer

The balanced chemical equation is O3 + 2I^- + H2O → I2 + 2OH^- + O2. The sum of the stoichiometric coefficients is 1 (O3) + 2 (I^-) + 1 (H2O) + 1 (I2) + 2 (OH^-) + 1 (O2) = 8.

Question 11

Which statement, A-D, regarding the carbon cycle is not correct?

Accepted Answer

All statements A through D are correct regarding the carbon cycle. Petroleum and coal are carbon sediments, respiration does produce CO2, water is indeed a reactant in photosynthesis, and forest fires contribute to the carbon cycle by releasing stored carbon.

Question 12

Air bags in cars inflate when an electrical spark activates sodium azide (NaN₃), so that it decomposes to sodium metal, Na, and nitrogen gas, N₂. In the balanced reaction equation, how many moles of nitrogen gas are formed for each mole of sodium azide?

Accepted Answer

The answer of Air bags in cars inflate when an...

Question 13

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

The balanced chemical equation for the reaction between phosphoric acid (H₃PO₄) and calcium hydroxide (Ca(OH)₂) to produce calcium phosphate (Ca₃(PO₄)₂) and water (H₂O) is: 2H₃PO₄ + 3Ca(OH)₂ → Ca₃(PO₄)₂ + 6H₂O. This shows that for each mole of calcium phosphate produced, 6 moles of water are produced.

Question 14

Fuming sulfuric acid is obtained by the addition of SO₃ to concentrated H₂SO₄. The fumes result from the reaction of SO₃ gas with water vapor. What is the product when one molecule of SO₃ reacts with one molecule of water?

Accepted Answer

When one molecule of SO₃ reacts with one molecule of water, it forms one molecule of sulfuric acid (H2SO4).

Question 15

Glucose (C₆H₁₂O₆) is oxidized by molecular oxygen to carbon dioxide and water. How many O₂ molecules are needed for each molecule of glucose that is oxidized?

Accepted Answer

The balanced chemical equation for the oxidation of glucose (C6H12O6) by molecular oxygen (O2) to produce carbon dioxide (CO2) and water (H2O) is: C6H12O6 + 6O2 -> 6CO2 + 6H2O. Therefore, 6 molecules of O2 are needed for each molecule of glucose.

Question 16

The combustion of ethanol (CH₃CH₂OH, 46.1 g/mol) results in the formation of water and carbon dioxide. How many grams of carbon dioxide are produced when 46.1 g of ethanol burns?

Accepted Answer

The answer of The combustion of ethanol (CH₃CH₂OH, 46.1 g/mol)...

Question 17

A fuel cell works on the same principle as a battery but is continually fed with fuel. In one fuel cell, methanol (CH₃OH) enters on one side of the unit, and air enters on the other side. Both circulate past electrodes, and a chemical reaction occurs that produces electricity plus carbon dioxide and water as byproducts. Which chemical reaction equation best represents the reaction that occurs in this fuel cell?

Accepted Answer

The correct balanced chemical equation for the reaction in a methanol fuel cell is 2CH₃OH + 3O₂ → 2CO₂ + 4H₂O, which represents the complete oxidation of methanol to carbon dioxide and water.

Question 18

A balanced chemical reaction equation is to a reactant as __________

Accepted Answer

A balanced chemical reaction equation shows the amounts of all the reactants and products involved in a chemical reaction, just as a recipe shows the amounts of all the ingredients needed to make a dish.

Question 19

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

When one molecule of sulfur dioxide (SO2) reacts with one molecule of water (H2O), the product is one molecule of sulfurous acid (H2SO3).

Question 20

The combustion of butane (C₄H₁₀) forms carbon dioxide and water. What is the stoichiometric coefficient for oxygen in the balanced equation when 1 mol of butane undergoes combustion?

Accepted Answer

The answer of The combustion of butane (C₄H₁₀) forms carbon...

Quiz 3: Chemical Reactions and Earths Composition

If the combustion of fossil fuels adds about 5 *10¹² kg of carbon to the atmosphere as CO₂ each year, how much oxygen is required to produce this amount of carbon dioxide?

Fe₂O₃(s) and powdered aluminum can react with great output of heat to form molten iron and Al₂O₃. When this reaction equation is balanced, what are the stoichiometric coefficients in the following order: Fe₂O₃, Al, Fe, Al₂O₃?

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?

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

Identify the set of stoichiometric coefficients that balance the reaction equation for the combustion of octane. C₈H₁₈ + O₂ $\rightarrow$ CO₂ + H₂O

The average adult exhales about 1.0 kg of carbon dioxide each day. How much oxygen is needed in metabolizing glucose (C₆H₁₂O₆, 180 g/mol) to make that much carbon dioxide?

Diesel fuel for automobiles and trucks is a mixture of hydrocarbons that can be modeled by C₁₆H₃₄. Write the balanced reaction equation for the combustion of C₁₆H₃₄, and report the sum of the stoichiometric coefficients.

Which statement, A-D, regarding photosynthesis is not correct? In the process of photosynthesis __________

Ozone (O₃) reacts with iodide (I^-) and water to form iodine (I₂) , hydroxide (OH^-) , and oxygen (O₂) . What is the sum of the stoichiometric coefficients in the balanced reaction equation? O₃ + I^- + H₂O $\rightarrow$ I₂ + OH^- + O₂

Which statement, A-D, regarding the carbon cycle is not correct?

Air bags in cars inflate when an electrical spark activates sodium azide (NaN₃) , so that it decomposes to sodium metal, Na, and nitrogen gas, N₂. In the balanced reaction equation, how many moles of nitrogen gas are formed for each mole of sodium azide?

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?

Fuming sulfuric acid is obtained by the addition of SO₃ to concentrated H₂SO₄. The fumes result from the reaction of SO₃ gas with water vapor. What is the product when one molecule of SO₃ reacts with one molecule of water?

Glucose (C₆H₁₂O₆) is oxidized by molecular oxygen to carbon dioxide and water. How many O₂ molecules are needed for each molecule of glucose that is oxidized?

The combustion of ethanol (CH₃CH₂OH, 46.1 g/mol) results in the formation of water and carbon dioxide. How many grams of carbon dioxide are produced when 46.1 g of ethanol burns?

A balanced chemical reaction equation is to a reactant as __________

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?

The combustion of butane (C₄H₁₀) forms carbon dioxide and water. What is the stoichiometric coefficient for oxygen in the balanced equation when 1 mol of butane undergoes combustion?

Quiz 3: Chemical Reactions and Earths Composition

If the combustion of fossil fuels adds about 5 *1012 kg of carbon to the atmosphere as CO2 each year, how much oxygen is required to produce this amount of carbon dioxide?

Fe2O3(s) and powdered aluminum can react with great output of heat to form molten iron and Al2O3. When this reaction equation is balanced, what are the stoichiometric coefficients in the following order: Fe2O3, Al, Fe, Al2O3?

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?

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

Identify the set of stoichiometric coefficients that balance the reaction equation for the combustion of octane. C8H18 + O2 →\rightarrow→ CO2 + H2O

The average adult exhales about 1.0 kg of carbon dioxide each day. How much oxygen is needed in metabolizing glucose (C6H12O6, 180 g/mol) to make that much carbon dioxide?

Diesel fuel for automobiles and trucks is a mixture of hydrocarbons that can be modeled by C16H34. Write the balanced reaction equation for the combustion of C16H34, and report the sum of the stoichiometric coefficients.

Which statement, A-D, regarding photosynthesis is not correct? In the process of photosynthesis __________

Ozone (O3) reacts with iodide (I-) and water to form iodine (I2) , hydroxide (OH-) , and oxygen (O2) . What is the sum of the stoichiometric coefficients in the balanced reaction equation? O3 + I- + H2O →\rightarrow→ I2 + OH- + O2

Which statement, A-D, regarding the carbon cycle is not correct?

Air bags in cars inflate when an electrical spark activates sodium azide (NaN3) , so that it decomposes to sodium metal, Na, and nitrogen gas, N2. In the balanced reaction equation, how many moles of nitrogen gas are formed for each mole of sodium azide?

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?

Fuming sulfuric acid is obtained by the addition of SO3 to concentrated H2SO4. The fumes result from the reaction of SO3 gas with water vapor. What is the product when one molecule of SO3 reacts with one molecule of water?

Glucose (C6H12O6) is oxidized by molecular oxygen to carbon dioxide and water. How many O2 molecules are needed for each molecule of glucose that is oxidized?

The combustion of ethanol (CH3CH2OH, 46.1 g/mol) results in the formation of water and carbon dioxide. How many grams of carbon dioxide are produced when 46.1 g of ethanol burns?

A balanced chemical reaction equation is to a reactant as __________

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?

The combustion of butane (C4H10) forms carbon dioxide and water. What is the stoichiometric coefficient for oxygen in the balanced equation when 1 mol of butane undergoes combustion?

If the combustion of fossil fuels adds about 5 *10¹² kg of carbon to the atmosphere as CO₂ each year, how much oxygen is required to produce this amount of carbon dioxide?

Fe₂O₃(s) and powdered aluminum can react with great output of heat to form molten iron and Al₂O₃. When this reaction equation is balanced, what are the stoichiometric coefficients in the following order: Fe₂O₃, Al, Fe, Al₂O₃?

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

Identify the set of stoichiometric coefficients that balance the reaction equation for the combustion of octane. C₈H₁₈ + O₂ $\rightarrow$ CO₂ + H₂O

The average adult exhales about 1.0 kg of carbon dioxide each day. How much oxygen is needed in metabolizing glucose (C₆H₁₂O₆, 180 g/mol) to make that much carbon dioxide?

Diesel fuel for automobiles and trucks is a mixture of hydrocarbons that can be modeled by C₁₆H₃₄. Write the balanced reaction equation for the combustion of C₁₆H₃₄, and report the sum of the stoichiometric coefficients.

Ozone (O₃) reacts with iodide (I^-) and water to form iodine (I₂) , hydroxide (OH^-) , and oxygen (O₂) . What is the sum of the stoichiometric coefficients in the balanced reaction equation? O₃ + I^- + H₂O $\rightarrow$ I₂ + OH^- + O₂

Air bags in cars inflate when an electrical spark activates sodium azide (NaN₃) , so that it decomposes to sodium metal, Na, and nitrogen gas, N₂. In the balanced reaction equation, how many moles of nitrogen gas are formed for each mole of sodium azide?

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?

Fuming sulfuric acid is obtained by the addition of SO₃ to concentrated H₂SO₄. The fumes result from the reaction of SO₃ gas with water vapor. What is the product when one molecule of SO₃ reacts with one molecule of water?

Glucose (C₆H₁₂O₆) is oxidized by molecular oxygen to carbon dioxide and water. How many O₂ molecules are needed for each molecule of glucose that is oxidized?

The combustion of ethanol (CH₃CH₂OH, 46.1 g/mol) results in the formation of water and carbon dioxide. How many grams of carbon dioxide are produced when 46.1 g of ethanol burns?

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?

The combustion of butane (C₄H₁₀) forms carbon dioxide and water. What is the stoichiometric coefficient for oxygen in the balanced equation when 1 mol of butane undergoes combustion?