Question 1

The space shuttle uses liquid hydrogen and liquid oxygen to produce thrust for liftoff in the following reaction: 2 H₂(l)+ O₂( )$\to$ 2 H₂O(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

From the equation:

2 H2(l) + O2(g) -> 2 H2O(l)

We can see that the ratio of hydrogen to oxygen needed is 2:1. Therefore, the rate of liquid hydrogen supply needs to be half of the rate of liquid oxygen supply, which is:

420 kg/s ÷ 2 = 210 kg/s

Therefore, the correct answer is D) 52.9 kg/s.

Question 2

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)results in...

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

To solve this problem, we need to use the information given to us to determine the amount of water that was originally present in the hydrate.

First, we need to calculate the mass of water that was driven off during heating:
Mass of water = 100.0 g - 65.36 g = 34.64 g

Next, we need to convert the mass of water to moles using the molar mass of water:
34.64 g / 18.015 g/mol = 1.921 mol

Finally, we need to use the mole ratio between water and hydrated aluminum oxide to determine the value of x in the molecular formula:
1.921 mol H2O / 1 mol Al2O3•xH2O

To find the value of x, we need to use a whole number ratio between the moles of water and the moles of hydrated aluminum oxide. The simplest whole number ratio is 3:1, which means that there are 3 moles of water for every 1 mole of hydrated aluminum oxide. Therefore, the value of x is 3.

The correct answer is C (3).

Question 4

As ammonium hydrogen carbonate (NH₄HCO₃,79.1 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 (NH₄HCO₃,79.1 g/mol)is heated,it...

Question 5

Suppose the combustion of fossil fuels adds about 8.0 $\times$ 10¹² kg of carbon to the atmosphere per year in the form of CO₂.How much oxygen gas is required to produce this amount of carbon dioxide?

Accepted Answer

The combustion of carbon to form CO2 requires one mole of O2 for each mole of carbon. The molar mass of carbon is 12 g/mol, and the molar mass of O2 is 32 g/mol. Therefore, for 8.0 x 10^12 kg of carbon, the required oxygen is (32/12) times that mass, which is approximately 2.1 x 10^13 kg.

Question 6

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

Accepted Answer

All the statements A-D are correct descriptions of processes involved in the carbon cycle.

Question 7

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% H₂O₂ (by mass)decomposes completely,how many liters of oxygen gas would 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 2 H₂O₂(aq)$\to$ 2 H₂O( )+ O₂(g)

Accepted Answer

The answer of Hydrogen peroxide (H₂O₂)decomposes catalytically in the presence...

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 of Cu is 63.55 g/mol, so for two Cu atoms, it's 127.1 g/mol. The molar mass of (OH)2 is 34.02 g/mol, and CO3 is 60.01 g/mol. The total molar mass of malachite is 127.1 + 34.02 + 60.01 = 221.13 g/mol. The mass percent of copper is (127.1/221.13) * 100% = 57.5%.

Question 9

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

Accepted Answer

One molecule of glucose produces 6 molecules of carbon dioxide during cellular respiration. Therefore, to produce 1 kg (1000 g) of carbon dioxide, 166.7 g (1000/6) of glucose would be consumed. To produce 1.0 kg of carbon dioxide, 166.7 g of glucose would be consumed, which is equal to 0.1667 kg. Therefore, to exhale 1.0 kg of carbon dioxide each day, about 0.1667 kg of glucose would be consumed.

Question 10

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

Accepted Answer

The balanced chemical equation for the combustion of butane is:

2C4H10 + 13O2 → 8CO2 + 10H2O

From this equation, we can see that for every 13 moles of oxygen consumed, we need 2 moles of butane. We can use this ratio to convert the given mass of oxygen to the mass of butane required:

32.0 g O2 x (1 mol O2/32.00 g O2) x (2 mol C4H10/13 mol O2) x (58.12 g C4H10/1 mol C4H10) = 8.94 g C4H10

Therefore, the answer is E) 8.94 g.

Question 11

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

Accepted Answer

The balanced chemical equation for the combustion of butane is:

2 C4H10 + 13 O2 → 8 CO2 + 10 H2O

From this equation, we can see that 2 moles of butane would produce 8 moles of CO2.

4.00 mol butane x (8 mol CO2 / 2 mol butane) x (44.01 g CO2 / 1 mol CO2) = 704 g CO2

Therefore, the complete combustion of 4.00 mol butane would result in the production of 704 g of CO2, which is the same as the mass of COS in the question.

Question 12

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? 2 H₂O( )$\to$ 2 H₂(g)+ O₂(g)

Accepted Answer

The answer of Water can be separated into its elements...

Question 13

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 g/mol.

Accepted Answer

Step 1: Find the molar mass of C₁₆H₃₄ molar mass = (11 x 12.01 g/mol) + (1 x 1.01 g/mol) + (16 x 32.06 g/mol) + (1 x 1.01 g/mol) + (34 x 1.01 g/mol) + (1 x 32.06 g/mol) + (1 x 1.01 g/mol) + (34 x 1.01 g/mol) = 226 g/mol Step 2: Use the balanced equation to determine the mole ratio between C₁₆H₃₄ and O₂ C₁₆H₃₄ + 15O₂ → 8CO2 + 9H2O + 15SO2 1 mol C₁₆H₃₄ : 15 mol O₂ Step 3: Convert 1.00 mol O₂ to mol C₁₆H₃₄ using the mole ratio 1.00 mol O₂ x (1 mol C₁₆H₃₄ / 15 mol O₂) = 0.06667 mol C₁₆H₃₄ Step 4: Convert mol of C₁₆H₃₄ to mL using the density of C₁₆H₃₄ 0.06667 mol C₁₆H₃₄ x (226 g/mol / 0.773 g/mL) x (1 mL/1.00 g) = 11.9 mL C₁₆H₃₄

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 KAl₁₃ (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 grams of Al₂O₃? You will need to write a balanced chemical reaction.

Accepted Answer

The answer of Aluminum can form clusters that behave similarly...

Question 15

How much CO₂ is produced by a car driven 20,000 mi in one year? Assume the following: • A car gets 20 mi/4.0 L of gasoline. • Gasoline has the chemical formula of octane: C₈H₁₈. • One liter of gasoline has a mass of 0.8 kg. • Gasoline is completely burned to carbon dioxide and water.

Accepted Answer

The answer of How much CO₂ is produced by a...

Question 16

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 17

Global carbon emissions in 2010 were estimated to be on the order of 9.0 $\times$ 10¹² metric tons carbon (1 metric ton = 1000 kg)in the form of CO₂.This is equivalent to __________ kg C.

Accepted Answer

1 metric ton = 1000 kg9.0 F1F1F1S1F1F1F10 10¹² metric tons carbon = 9.0 F1F1F1S1F1F1F10 10¹² * 1000 kg = 9.0 F1F1F1S1F1F1F10 10¹⁵ kg

Question 18

Copper(II)sulfate (CuSO₄)can be used to control algae growth.Aqueous CuSO₄ solutions that come in contact with the surface of galvanized (zinc-plated)steel pails undergo the following reaction: CuSO₄(aq)+ Zn(s)$\to$ Cu(s)+ ZnSO₄(aq) How many grams of zinc would react with 454 g (1 lb)of CuSO₄ (160 g/mol)?

Accepted Answer

From the balanced chemical equation, the mole ratio between CuSO4 and Zn is 1:1. Therefore, 454 g CuSO4 (1 lb) is equal to 2.84 moles. To react completely with this amount of CuSO4, we need 2.84 moles of Zn. 
Using the molar mass of CuSO4 (160 g/mol), we can calculate that the weight of 2.84 moles of CuSO4 is 454 g. 
Therefore, we need 2.84 moles or 186 g of zinc to react with 454 g of CuSO4. 
The correct answer is B) 186 g.

Question 19

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

Accepted Answer

From the given hydrocarbon mixture, we can see that for every 1 mol of C₁₆H₃₄, we need 12 mol of O₂ for complete combustion. Therefore, for 0.500 mol of C₁₆H₃₄, we need 6.00 mol of O₂. To find the mass of O₂ needed, we can use the molar mass of O₂, which is 16.00 g/mol. Mass of O₂ = number of moles x molar mass Mass of O₂ = 6.00 mol x 16.00 g/mol = 96.00 g Therefore, the answer is B) 392 g.

Question 20

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 answer of Arizona was the site of a 400,000-acre...

Quiz 7: Stoichiometry-Mass Relationships and Chemical 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?

As ammonium hydrogen carbonate (NH₄HCO₃,79.1 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?

Suppose the combustion of fossil fuels adds about 8.0 $\times$ 10¹² kg of carbon to the atmosphere per year in the form of CO₂.How much oxygen gas is required to produce this amount of carbon dioxide?

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

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?

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

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

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

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 g/mol.

How much CO₂ is produced by a car driven 20,000 mi in one year? Assume the following: • A car gets 20 mi/4.0 L of gasoline. • Gasoline has the chemical formula of octane: C₈H₁₈. • One liter of gasoline has a mass of 0.8 kg. • Gasoline is completely burned to carbon dioxide and water.

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

Global carbon emissions in 2010 were estimated to be on the order of 9.0 $\times$ 10¹² metric tons carbon (1 metric ton = 1000 kg) in the form of CO₂.This is equivalent to __________ kg C.

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

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) .

Quiz 7: Stoichiometry-Mass Relationships and Chemical 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?

As ammonium hydrogen carbonate (NH4HCO3,79.1 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?

Suppose the combustion of fossil fuels adds about 8.0 ×\times× 1012 kg of carbon to the atmosphere per year in the form of CO2.How much oxygen gas is required to produce this amount of carbon dioxide?

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

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?

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

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

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

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? 2 H2O( ) →\to→ 2 H2(g) + O2(g)

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 g/mol.

How much CO2 is produced by a car driven 20,000 mi in one year? Assume the following: • A car gets 20 mi/4.0 L of gasoline. • Gasoline has the chemical formula of octane: C8H18. • One liter of gasoline has a mass of 0.8 kg. • Gasoline is completely burned to carbon dioxide and water.

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

Global carbon emissions in 2010 were estimated to be on the order of 9.0 ×\times× 1012 metric tons carbon (1 metric ton = 1000 kg) in the form of CO2.This is equivalent to __________ kg C.

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

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,46.1 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?

As ammonium hydrogen carbonate (NH₄HCO₃,79.1 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?

Suppose the combustion of fossil fuels adds about 8.0 $\times$ 10¹² kg of carbon to the atmosphere per year in the form of CO₂.How much oxygen gas is required to produce this amount of carbon dioxide?

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?

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

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

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

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 g/mol.

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

Global carbon emissions in 2010 were estimated to be on the order of 9.0 $\times$ 10¹² metric tons carbon (1 metric ton = 1000 kg) in the form of CO₂.This is equivalent to __________ kg C.

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

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) .