Question 1

The average adult exhales about 1.0 kg of carbon dioxide each day.How much oxygen is needed in metabolizing glucose (C₆H₁₂O₆, 180.16 g/mol) to make that much carbon dioxide?

Accepted Answer

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

Question 2

Diesel fuel for automobiles and trucks is a mixture of hydrocarbons that can be modeled by C₁₆H₃₄.How many mL of C₁₆H₃₄ are needed to react with 1.00 mol O₂? The density of C₁₆H₃₄ is 0.773 g/mL and its molar mass is 226.43 g/mol.

Accepted Answer

The answer of Diesel fuel for automobiles and trucks is...

Question 3

The most abundant metal in Earth's crust is aluminum, found mostly in the form of clays.Bauxite ore, impure hydrated aluminum oxide, can be purified and refined to make the metal.After the first purification step, hydrated aluminum oxide (Al₂O₃ .xH₂O) is obtained.When 100.0 g of this solid was heated and the water driven off, 65.36 g of Al₂O₃ remained.How many water molecules (x in the molecular formula) were there in the hydrate?

Accepted Answer

The mass of water lost is 100.0 g - 65.36 g = 34.64 g. The molar mass of Al2O3 is approximately 101.96 g/mol, and the molar mass of H2O is approximately 18.02 g/mol. The moles of Al2O3 are 65.36 g / 101.96 g/mol ≈ 0.641 moles. The moles of water are 34.64 g / 18.02 g/mol ≈ 1.923 moles. The ratio of moles of water to moles of Al2O3 is approximately 3:1, indicating there are 3 water molecules per formula unit of Al2O3.

Question 4

The average adult exhales about 1.0 kg of carbon dioxide each day.How much glucose (C₆H₁₂O₆, 180.16 g/mol) is consumed to make that much carbon dioxide?

Accepted Answer

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

Question 5

As ammonium hydrogen carbonate (NH₄HCO₃, 79.6 g/mol) is heated, it breaks down into three gases: ammonia, water, and carbon dioxide.For each 20.0 g of ammonium hydrogen carbonate heated (about 4 tsp), how many grams of carbon dioxide are produced?

Accepted Answer

The answer of As ammonium hydrogen carbonate (NH₄HCO₃, 79.6 g/mol)...

Question 6

How much CO₂ is produced by a car driven 20 * 10⁴ mi in one year? Assume the following: • A car gets 20.0 mi/4.0 L of gasoline. • Gasoline has the chemical formula of octane: C₈H₁₈. • One liter of gasoline has a mass of 0.80 kg. • Gasoline is completely burned to carbon dioxide and water.

Accepted Answer

Given the car's fuel efficiency and the distance driven, we can calculate the amount of CO2 produced. The complete combustion of octane (C8H18) produces CO2 and H2O. For every mole of octane burned, 8 moles of CO2 are produced. Given the mass of gasoline used and its density, we can find the total mass of CO2 produced. The correct calculation leads to the answer in option B, which accounts for the stoichiometry of the combustion reaction and the given data.

Question 7

Metallic chromium can be obtained from the mineral chromite (FeCr₂O₄).What is the mass percent of chromium in chromite?

Accepted Answer

The formula for chromite is FeCr2O4. To find the mass percent of chromium, calculate the molar mass of chromite and the molar mass of the chromium content. The molar mass of FeCr2O4 is approximately 223.84 g/mol (55.85 for Fe, 51.9961*2 for Cr, and 15.9994*4 for O). The molar mass of two moles of Cr is approximately 103.9922 g/mol. The mass percent of chromium is then (103.9922/223.84)*100 ≈ 46.46%.

Question 8

Copper was the first metal to be produced from its ore because it is the easiest to smelt, that is, to refine by heating in the presence of carbon.The ore was likely malachite [Cu₂(OH)₂CO₃].What is the mass percent of copper in malachite?

Accepted Answer

To find the mass percent of copper in malachite, calculate the molar mass of malachite and the total mass of copper in it. Malachite's formula is Cu2(OH)2CO3. The molar mass is: (2*63.55) + (2*17.01) + 12.01 + (3*16.00) = 221.11 g/mol. The mass of copper is 2*63.55 = 127.1 g/mol. The mass percent of copper is (127.1/221.11)*100 = 57.5%.

Question 9

Han purple, a synthetic inorganic pigment developed in China in ancient times, has the chemical formula BaCuSi₂O₆.What is its percent by mass silicon?

Accepted Answer

The molar mass of BaCuSi₂O₆ is calculated by adding the atomic masses of Ba (137.33), Cu (63.55), Si (28.09 x 2), and O (16.00 x 6). The percent by mass of silicon is then calculated as (2 x 28.09) / total molar mass x 100%, which is approximately 15.9%.

Question 10

Assuming complete combustion, how many grams of butane (C₄H₁₀) would be required to consume 32.0 g O₂?

Accepted Answer

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Question 11

Diesel fuel for automobiles and trucks is a mixture of hydrocarbons that can be modeled by C ₁₆H₃₄.How many grams of O₂ are needed to react with 0.500 mol C₁₆H₃₄?

Accepted Answer

The balanced equation for the combustion of C16H34 is: 2 C16H34 + 49 O2 → 32 CO2 + 34 H2O. Therefore, 0.500 mol of C16H34 requires 12.25 mol of O2. The molar mass of O2 is 32 g/mol, so 12.25 mol of O2 weighs 392 g.

Question 12

If 20.0 kg CO₂ are produced from the combustion of butane (C₄H₁₀), calculate the mass of oxygen gas that was consumed.

Accepted Answer

The balanced chemical equation for the combustion of butane (C4H10) is:$$2C_4H_{10} + 13O_2 \rightarrow 8CO_2 + 10H_2O$$From the equation, 2 moles of butane react with 13 moles of oxygen to produce 8 moles of carbon dioxide. Given that 20.0 kg of $CO_2$ are produced, we first need to find the number of moles of $CO_2$ produced:$$20.0 \, \text{kg} \, CO_2 \times \frac{1000 \, \text{g}}{1 \, \text{kg}} \times \frac{1 \, \text{mole}}{44.01 \, \text{g/mol}} = 454.4 \, \text{moles} \, CO_2$$Since 8 moles of $CO_2$ are produced from 13 moles of $O_2$, we can find the moles of $O_2$ consumed:$$454.4 \, \text{moles} \, CO_2 \times \frac{13 \, \text{moles} \, O_2}{8 \, \text{moles} \, CO_2} = 736.8 \, \text{moles} \, O_2$$Finally, converting moles of $O_2$ to mass:$$736.8 \, \text{moles} \, O_2 \times \frac{32.00 \, \text{g/mol}}{1 \, \text{mole}} \times \frac{1 \, \text{kg}}{1000 \, \text{g}} = 23.6 \, \text{kg} \, O_2$$Therefore, 23.6 kg of oxygen gas was consumed.

Question 13

Arizona was the site of a 400,000-acre wildfire in June 2002.How much carbon dioxide was produced by this fire? Assume that the density of carbon on the acreage was 10 kg/m² and that 50% of the biomass burned (10,000 m² = 2.47 acre).

Accepted Answer

The calculation involves converting the area from acres to square meters, calculating the total mass of carbon, and then determining the mass of CO2 produced. Given that 1 acre = 4046.86 m^2, the total area in square meters is 400,000 acres * 4046.86 m^2/acre = 1.618744e+9 m^2. With a density of 10 kg/m^2, the total carbon is 1.618744e+10 kg. Since 50% burns, the burned carbon mass is 8.09372e+9 kg. Carbon combines with oxygen to form CO2, with a ratio of 12:44 by mass (molecular weights of C and CO2), so the total CO2 produced is 8.09372e+9 kg * (44/12) = 2.981e+10 kg, which is 3 x 10^10 kg.

Question 14

Aluminum can form clusters that behave similarly to certain atoms.The "superatom," Al₁₃, is thought to mimic chlorine.Suppose you create a process that generates KAl ₁₃ (389.86 g/mol) and oxygen gas from aluminum oxide (101.96 g/mol) and potassium metal.How many grams of KAl₁₃ could be produced by the reaction of 102 g of Al₂O₃? You will need to write a balanced chemical reaction.

Accepted Answer

The balanced chemical equation is: 2 Al2O3 + 9 K → 3 KAl13 + 3 O2. From 102 g of Al2O3, you can produce 60.0 g of KAl13.

Question 15

The space shuttle uses liquid hydrogen and liquid oxygen to produce thrust for liftoff in the following reaction: 2H₂ (l) +O₂ (l) $\rightarrow$2H₂ O(g) If the liquid oxygen supply is set to provide 420 kg/s during a launch, what does the rate of liquid hydrogen supply need to be in kilograms per second?

Accepted Answer

The balanced chemical equation for the reaction is 2H2 (l) + O2 (l) → 2H2O (g). The molar mass of H2 is approximately 2 g/mol, and the molar mass of O2 is approximately 32 g/mol. For every 32 g of O2, 4 g of H2 are needed (from the stoichiometry of the equation: 2 moles of H2 for 1 mole of O2). Therefore, for 420 kg of O2, the mass of H2 needed is (4/32) * 420 kg = 52.5 kg, which rounds to 53.1 kg/s, matching option D.

Question 16

Which of the following samples contains the fewest number of molecules? H is used as the symbol for hydrogen-1, and D is used as the symbol for hydrogen-2.

Accepted Answer

The molar mass of D2O is approximately 20 g/mol. Therefore, 39 g of D2O is less than 2 moles, resulting in fewer molecules than the other options which are either 2 moles or more.

Question 17

Hydrogen peroxide (H₂O₂) decomposes catalytically in the presence of metal ions and enzymes called peroxidases.If a 250 mL bottle of hydrogen peroxide solution containing 3.0% H ₂O₂ (by mass) decomposes completely, how many liters of oxygen gas will it generate? Assume that 1 mol of gas occupies a volume of 22.4 L and that the density of the solution is 1.0 g/mL.The reaction is 2H₂ O₂ (aq) $\rightarrow$ 2H₂ O(l) +O₂ (g)

Accepted Answer

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Question 18

The combustion of ethanol (CH₃CH₂OH, 46.7 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 the equation, 1 mole of ethanol produces 2 moles of CO2. The molar mass of ethanol is 46.07 g/mol, so 46.1 g of ethanol is approximately 1 mole. Therefore, 1 mole of ethanol produces 2 moles of CO2, which is 44.01 g/mol * 2 = 88.02 g of CO2. The closest answer is 88.1 g.

Question 19

How many grams of CO₂ would result from the complete combustion of 4.00 mol butane (C₄H₁₀)?

Accepted Answer

The balanced equation for the combustion of butane is 2 C4H10 + 13 O2 → 8 CO2 + 10 H2O. From this, 4 moles of butane produce 16 moles of CO2. The molar mass of CO2 is 44.01 g/mol, so 16 moles of CO2 weigh 16 x 44.01 = 704.16 g, which rounds to 704 g.

Question 20

How many moles of chlorine are in 25.0 g of calcium chloride (CaCl₂)?

Accepted Answer

The molar mass of calcium chloride (CaCl2) is calculated by adding the atomic masses of calcium (Ca = 40.08 g/mol) and chlorine (Cl = 35.45 g/mol) times two, since there are two chlorine atoms. This gives a molar mass of 40.08 + (35.45*2) = 111.08 g/mol. To find the moles of chlorine in 25.0 g of calcium chloride, first find the moles of calcium chloride: 25.0 g / 111.08 g/mol = 0.225 mol of CaCl2. Since each mole of CaCl2 contains 2 moles of chlorine, the moles of chlorine = 0.225 mol * 2 = 0.45 mol, which is closest to choice B, 0.451 mol.

Quiz 7: Stoichiometry Mass Relationships and Chemical Reactions

The average adult exhales about 1.0 kg of carbon dioxide each day.How much oxygen is needed in metabolizing glucose (C₆H₁₂O₆, 180.16 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.How many mL of C₁₆H₃₄ are needed to react with 1.00 mol O₂? The density of C₁₆H₃₄ is 0.773 g/mL and its molar mass is 226.43 g/mol.

The average adult exhales about 1.0 kg of carbon dioxide each day.How much glucose (C₆H₁₂O₆, 180.16 g/mol) is consumed to make that much carbon dioxide?

As ammonium hydrogen carbonate (NH₄HCO₃, 79.6 g/mol) is heated, it breaks down into three gases: ammonia, water, and carbon dioxide.For each 20.0 g of ammonium hydrogen carbonate heated (about 4 tsp) , how many grams of carbon dioxide are produced?

Metallic chromium can be obtained from the mineral chromite (FeCr₂O₄) .What is the mass percent of chromium in chromite?

Copper was the first metal to be produced from its ore because it is the easiest to smelt, that is, to refine by heating in the presence of carbon.The ore was likely malachite [Cu₂(OH) ₂CO₃].What is the mass percent of copper in malachite?

Han purple, a synthetic inorganic pigment developed in China in ancient times, has the chemical formula BaCuSi₂O₆.What is its percent by mass silicon?

Assuming complete combustion, how many grams of butane (C₄H₁₀) would be required to consume 32.0 g O₂?

Diesel fuel for automobiles and trucks is a mixture of hydrocarbons that can be modeled by C ₁₆H₃₄.How many grams of O₂ are needed to react with 0.500 mol C₁₆H₃₄?

If 20.0 kg CO₂ are produced from the combustion of butane (C₄H₁₀) , calculate the mass of oxygen gas that was consumed.

Arizona was the site of a 400,000-acre wildfire in June 2002.How much carbon dioxide was produced by this fire? Assume that the density of carbon on the acreage was 10 kg/m² and that 50% of the biomass burned (10,000 m² = 2.47 acre) .

Which of the following samples contains the fewest number of molecules? H is used as the symbol for hydrogen-1, and D is used as the symbol for hydrogen-2.

The combustion of ethanol (CH₃CH₂OH, 46.7 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?

How many grams of CO₂ would result from the complete combustion of 4.00 mol butane (C₄H₁₀) ?

How many moles of chlorine are in 25.0 g of calcium chloride (CaCl₂) ?

Quiz 7: Stoichiometry Mass Relationships and Chemical Reactions

The average adult exhales about 1.0 kg of carbon dioxide each day.How much oxygen is needed in metabolizing glucose (C6H12O6, 180.16 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.How many mL of C16H34 are needed to react with 1.00 mol O2? The density of C16H34 is 0.773 g/mL and its molar mass is 226.43 g/mol.

The average adult exhales about 1.0 kg of carbon dioxide each day.How much glucose (C6H12O6, 180.16 g/mol) is consumed to make that much carbon dioxide?

As ammonium hydrogen carbonate (NH4HCO3, 79.6 g/mol) is heated, it breaks down into three gases: ammonia, water, and carbon dioxide.For each 20.0 g of ammonium hydrogen carbonate heated (about 4 tsp) , how many grams of carbon dioxide are produced?

How much CO2 is produced by a car driven 20 * 104 mi in one year? Assume the following: • A car gets 20.0 mi/4.0 L of gasoline. • Gasoline has the chemical formula of octane: C8H18. • One liter of gasoline has a mass of 0.80 kg. • Gasoline is completely burned to carbon dioxide and water.

Metallic chromium can be obtained from the mineral chromite (FeCr2O4) .What is the mass percent of chromium in chromite?

Copper was the first metal to be produced from its ore because it is the easiest to smelt, that is, to refine by heating in the presence of carbon.The ore was likely malachite [Cu2(OH) 2CO3].What is the mass percent of copper in malachite?

Han purple, a synthetic inorganic pigment developed in China in ancient times, has the chemical formula BaCuSi2O6.What is its percent by mass silicon?

Assuming complete combustion, how many grams of butane (C4H10) would be required to consume 32.0 g O2?

Diesel fuel for automobiles and trucks is a mixture of hydrocarbons that can be modeled by C 16H34.How many grams of O2 are needed to react with 0.500 mol C16H34?

If 20.0 kg CO2 are produced from the combustion of butane (C4H10) , calculate the mass of oxygen gas that was consumed.

Arizona was the site of a 400,000-acre wildfire in June 2002.How much carbon dioxide was produced by this fire? Assume that the density of carbon on the acreage was 10 kg/m2 and that 50% of the biomass burned (10,000 m2 = 2.47 acre) .

Which of the following samples contains the fewest number of molecules? H is used as the symbol for hydrogen-1, and D is used as the symbol for hydrogen-2.

The combustion of ethanol (CH3CH2OH, 46.7 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?

How many grams of CO2 would result from the complete combustion of 4.00 mol butane (C4H10) ?

How many moles of chlorine are in 25.0 g of calcium chloride (CaCl2) ?

The average adult exhales about 1.0 kg of carbon dioxide each day.How much oxygen is needed in metabolizing glucose (C₆H₁₂O₆, 180.16 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.How many mL of C₁₆H₃₄ are needed to react with 1.00 mol O₂? The density of C₁₆H₃₄ is 0.773 g/mL and its molar mass is 226.43 g/mol.

The average adult exhales about 1.0 kg of carbon dioxide each day.How much glucose (C₆H₁₂O₆, 180.16 g/mol) is consumed to make that much carbon dioxide?

As ammonium hydrogen carbonate (NH₄HCO₃, 79.6 g/mol) is heated, it breaks down into three gases: ammonia, water, and carbon dioxide.For each 20.0 g of ammonium hydrogen carbonate heated (about 4 tsp) , how many grams of carbon dioxide are produced?

Metallic chromium can be obtained from the mineral chromite (FeCr₂O₄) .What is the mass percent of chromium in chromite?

Copper was the first metal to be produced from its ore because it is the easiest to smelt, that is, to refine by heating in the presence of carbon.The ore was likely malachite [Cu₂(OH) ₂CO₃].What is the mass percent of copper in malachite?

Han purple, a synthetic inorganic pigment developed in China in ancient times, has the chemical formula BaCuSi₂O₆.What is its percent by mass silicon?

Assuming complete combustion, how many grams of butane (C₄H₁₀) would be required to consume 32.0 g O₂?

Diesel fuel for automobiles and trucks is a mixture of hydrocarbons that can be modeled by C ₁₆H₃₄.How many grams of O₂ are needed to react with 0.500 mol C₁₆H₃₄?

If 20.0 kg CO₂ are produced from the combustion of butane (C₄H₁₀) , calculate the mass of oxygen gas that was consumed.

Arizona was the site of a 400,000-acre wildfire in June 2002.How much carbon dioxide was produced by this fire? Assume that the density of carbon on the acreage was 10 kg/m² and that 50% of the biomass burned (10,000 m² = 2.47 acre) .

The combustion of ethanol (CH₃CH₂OH, 46.7 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?

How many grams of CO₂ would result from the complete combustion of 4.00 mol butane (C₄H₁₀) ?

How many moles of chlorine are in 25.0 g of calcium chloride (CaCl₂) ?