Question 1

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 balanced chemical equation for the combustion of ethanol (C2H5OH) is: C2H5OH + 3O2 → 2CO2 + 3H2O. From this equation, 1 mole of ethanol produces 2 moles of CO2. Since 46.1 g of ethanol is equivalent to 1 mole (given its molar mass is 46.1 g/mol), burning 46.1 g of ethanol will produce 2 moles of CO2. The molar mass of CO2 is 44.0 g/mol, so 2 moles of CO2 weigh 2 * 44.0 g = 88.0 g.

Question 2

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? Note that the number of molecules of a gas is proportional to the volume of the gas at a given pressure and temperature.

Accepted Answer

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

Question 3

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 answer of The average adult exhales about 1.0 kg...

Question 4

Phosphorus trichloride reacts with water to form phosphorous acid, H₃PO₃, and hydrochloric acid in the following unbalanced reaction. For each mole of phosphorous acid produced by this reaction, how many moles of HCl are produced?__ PCl₃ __H₂O __H₃PO₃ + __ HCl

Accepted Answer

The answer of Phosphorus trichloride reacts with water to form...

Question 5

Respiration is to photosynthesis as ________

Accepted Answer

Respiration and photosynthesis are opposite processes; respiration releases energy by breaking down glucose, while photosynthesis stores energy by creating glucose, similar to how summer and winter are opposite seasons.

Question 6

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 7

Balance the following combustion reaction and report the sum of the stoichiometric coefficients.__ C₄H₈S₂ __O₂ __CO₂ __H₂O __SO₃

Accepted Answer

The answer of Balance the following combustion reaction and report...

Question 8

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 answer of What are the stoichiometric coefficients for oxygen...

Question 9

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 chemical equation for the combustion of the given mixture can be written as: C₁₆H₃₄ + 160(O2 + 3.76N2) → 116CO2 + 67H2O + 134SO2 + 600.96N2 The stoichiometric coefficients add up to (116+67+134+600.96) = 917.96. However, since the question asks for the sum of ONLY the stoichiometric coefficients, the answer is rounded down to the nearest whole number, which is 917. Therefore, the answer is E) 117 (digit sum of 917).

Question 10

The combustion of heptane (C₇H₁₆) forms carbon dioxide and water. What is the stoichiometric coefficient for water in the balanced equation when 1 mol of heptane undergoes combustion?

Accepted Answer

The answer of The combustion of heptane (C₇H₁₆) forms carbon...

Question 11

If the combustion of fossil fuels adds about 5 $\times$ 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 answer of If the combustion of fossil fuels adds...

Question 12

Ozone (O₃) reacts with iodide (I^-) and water to form iodine (I₂), hydroxide (OH^-), and oxygen (O₂). Balance the following reaction equation and report the sum of the stoichiometric coefficients. O₃ I^- H₂O I₂ OH^- O₂

Accepted Answer

The balanced equation is:
3 O3 + 6 I- + 6 H2O → 6 OH- + 6 O2 + 3 I2
Therefore, the sum of stoichiometric coefficients is 8.

Question 13

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 14

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

One mole of S8 reacts with 12 moles of O2 to produce 8 moles of SO3.

Question 15

The combustion of fossil fuels is the main anthropogenic source of carbon dioxide in the atmosphere. During the combustion of gasoline in automobile engines, oxygen reacts with hydrocarbons to produce carbon dioxide and water. Assume gasoline is octane (C₈H₁₈). Write the balanced reaction equation, and report the sum of the stoichiometric coefficients written as integers.

Accepted Answer

The answer of The combustion of fossil fuels is the...

Question 16

Identify the set of stoichiometric coefficients that balances the reaction equation for the combustion of octane. C₈H₁₈ O₂ CO₂ H₂O

Accepted Answer

The balanced equation for the combustion of octane is:

C8H18 + 25O2 → 16CO2 + 18H2O

The set of stoichiometric coefficients that balances this equation is:
- C8H18: 2 (since 2 x 8 = 16 C atoms and 2 x 18 = 36 H atoms)
- O2: 25 (since 25 x 2 = 50 O atoms)
- CO2: 16 (since 16 x 1 = 16 C atoms)
- H2O: 18 (since 18 x 2 = 36 H atoms)

Therefore, the correct answer is D) 2, 25, 16, 18.

Question 17

Ammonia undergoes combustion to produce nitrogen monoxide and water, both as gases. Write the balanced equation for this reaction and report the sum of the stoichiometric coefficients, written as integers.

Accepted Answer

The balanced equation is 4 NH3 + 5 O2 → 4 NO + 6 H2O. The sum of the coefficients is 4 + 5 + 4 + 6 = 19.

Question 18

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 19

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 balanced chemical reaction equation best represents the reaction that occurs in this fuel cell?

Accepted Answer

The answer of A fuel cell works on the same...

Question 20

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

The balanced equation is:

4FeS2 +11O2 → 2Fe2O3 + 8SO2

Therefore, the sum of stoichiometric coefficients is 4+11+2+8=25. Thus, the correct answer is (D).

Quiz 3: Stoichiometry: Mass, Formulas, and Reactions

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?

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?

Phosphorus trichloride reacts with water to form phosphorous acid, H₃PO₃, and hydrochloric acid in the following unbalanced reaction. For each mole of phosphorous acid produced by this reaction, how many moles of HCl are produced? PCl₃ H₂O H₃PO₃ + HCl

Respiration is to photosynthesis as ________

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

Balance the following combustion reaction and report the sum of the stoichiometric coefficients. C₄H₈S₂ O₂ CO₂ H₂O __SO₃

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

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.

The combustion of heptane (C₇H₁₆) forms carbon dioxide and water. What is the stoichiometric coefficient for water in the balanced equation when 1 mol of heptane undergoes combustion?

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

Ozone (O₃) reacts with iodide (I^-) and water to form iodine (I₂) , hydroxide (OH^-) , and oxygen (O₂) . Balance the following reaction equation and report the sum of the stoichiometric coefficients. O₃ I^- H₂O I₂ OH^- O₂

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

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?

Identify the set of stoichiometric coefficients that balances the reaction equation for the combustion of octane. C₈H₁₈ O₂ CO₂ H₂O

Ammonia undergoes combustion to produce nitrogen monoxide and water, both as gases. Write the balanced equation for this reaction and report the sum of the stoichiometric coefficients, written as integers.

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?

Quiz 3: Stoichiometry: Mass, Formulas, and Reactions

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?

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?

Phosphorus trichloride reacts with water to form phosphorous acid, H3PO3, and hydrochloric acid in the following unbalanced reaction. For each mole of phosphorous acid produced by this reaction, how many moles of HCl are produced?__ PCl3 __H2O __H3PO3 + __ HCl

Respiration is to photosynthesis as ________

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

Balance the following combustion reaction and report the sum of the stoichiometric coefficients.__ C4H8S2 __O2 __CO2 __H2O __SO3

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

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.

The combustion of heptane (C7H16) forms carbon dioxide and water. What is the stoichiometric coefficient for water in the balanced equation when 1 mol of heptane undergoes combustion?

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

Ozone (O3) reacts with iodide (I-) and water to form iodine (I2) , hydroxide (OH-) , and oxygen (O2) . Balance the following reaction equation and report the sum of the stoichiometric coefficients. O3 I- H2O I2 OH- O2

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

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?

Identify the set of stoichiometric coefficients that balances the reaction equation for the combustion of octane. C8H18 O2 CO2 H2O

Ammonia undergoes combustion to produce nitrogen monoxide and water, both as gases. Write the balanced equation for this reaction and report the sum of the stoichiometric coefficients, written as integers.

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?

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?

Phosphorus trichloride reacts with water to form phosphorous acid, H₃PO₃, and hydrochloric acid in the following unbalanced reaction. For each mole of phosphorous acid produced by this reaction, how many moles of HCl are produced? PCl₃ H₂O H₃PO₃ + HCl

Balance the following combustion reaction and report the sum of the stoichiometric coefficients. C₄H₈S₂ O₂ CO₂ H₂O __SO₃

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

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.

The combustion of heptane (C₇H₁₆) forms carbon dioxide and water. What is the stoichiometric coefficient for water in the balanced equation when 1 mol of heptane undergoes combustion?

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

Ozone (O₃) reacts with iodide (I^-) and water to form iodine (I₂) , hydroxide (OH^-) , and oxygen (O₂) . Balance the following reaction equation and report the sum of the stoichiometric coefficients. O₃ I^- H₂O I₂ OH^- O₂

Identify the set of stoichiometric coefficients that balances the reaction equation for the combustion of octane. C₈H₁₈ O₂ CO₂ H₂O

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?