Question 1

If a sample of methane gas,CH₄,reacts completely with oxygen gas to give 1.75 g of water,what STP volume of methane reacted? CH₄(g)+ O₂(g)  CO₂(g)+ H₂O(l)

Accepted Answer

The answer of If a sample of methane gas,CH₄,reacts completely...

Question 2

Given the three-step Contact process for manufacturing sulfuric acid,H₂SO₄: S(s)+ O₂(g)→ SO₂(g)
2 SO₂(g)+ O₂(g)→ 2 SO₃(g)
SO₃(g)+ H₂O(l)→ H₂SO₄(aq)
What mass of sulfuric acid is produced from the reaction of 25.0 g of sulfur?

Accepted Answer

First, calculate the moles of sulfur used using its molar mass (32.06 g/mol). For 25.0 g of sulfur: moles = 25.0 g / 32.06 g/mol = 0.780 moles. The stoichiometry of the reaction shows that 1 mole of sulfur produces 1 mole of H₂SO₄. Therefore, 0.780 moles of sulfur will produce 0.780 moles of H₂SO₄. The molar mass of H₂SO₄ is approximately 98.08 g/mol, so the mass of H₂SO₄ produced is 0.780 moles * 98.08 g/mol = 76.5 g, which rounds to 76.4 g for the answer.

Question 3

Given the three-step "blast furnace" process that converts iron ore,Fe₂O₃,into molten "pig iron": 3 Fe₂O₃(l)+ CO(g)→ 2 Fe₃O₄(l)+ CO₂(g)
Fe₃O₄(l)+ CO(g)→ 3 FeO(l)+ CO₂(g)
FeO(l)+ CO(g)→ Fe(l)+ CO₂(g)
What mass of Fe₂O₃ is required to produce 1.00 metric ton (1000 kg)of iron?

Accepted Answer

To find the mass of $Fe_2O_3$ required to produce 1.00 metric ton (1000 kg) of iron, we need to use stoichiometry based on the balanced chemical equations provided. The overall reaction, combining the three steps, is:$$Fe_2O_3 + 3CO \rightarrow 2Fe + 3CO_2$$From the balanced equation, 1 mole of $Fe_2O_3$ produces 2 moles of $Fe$. The molar mass of $Fe_2O_3$ is approximately 159.7 g/mol, and the molar mass of $Fe$ is approximately 55.85 g/mol.To produce 1000 kg (or 1,000,000 g) of $Fe$, we calculate the moles of $Fe$ produced:$$1000\,kg \times \frac{1000\,g}{1\,kg} \times \frac{1\,mol\,Fe}{55.85\,g} \approx 17907\,mol\,Fe$$Since 1 mole of $Fe_2O_3$ produces 2 moles of $Fe$, the moles of $Fe_2O_3$ required are half of the moles of $Fe$ produced:$$17907\,mol\,Fe \times \frac{1\,mol\,Fe_2O_3}{2\,mol\,Fe} \approx 8953.5\,mol\,Fe_2O_3$$The mass of $Fe_2O_3$ required is then:$$8953.5\,mol \times 159.7\,g/mol \approx 1430000\,g$$Converting to kilograms:$$1430000\,g \times \frac{1\,kg}{1000\,g} = 1430\,kg$$Therefore, 1430 kg of $Fe_2O_3$ is required to produce 1.00 metric ton (1000 kg) of iron.

Question 4

Given the three-step "blast furnace" process that converts iron ore,Fe₂O₃,into molten "pig iron": 3 Fe₂O₃(l)+ CO(g)→ 2 Fe₃O₄(l)+ CO₂(g)
Fe₃O₄(l)+ CO(g)→ 3 FeO(l)+ CO₂(g)
FeO(l)+ CO(g)→ Fe(l)+ CO₂(g)
How many moles of iron are produced from the reaction of 6.00 mol of Fe₂O₃?

Accepted Answer

The overall stoichiometry, combining the three steps, shows that for every mole of Fe₂O₃ reacted, 2 moles of Fe are produced. Therefore, 6.00 moles of Fe₂O₃ would produce 12.0 moles of Fe.

Question 5

If a sample of ammonia gas,NH₃,reacts with oxygen and platinum catalyst to give 55.5 L of nitrogen monoxide gas at STP,what mass of ammonia reacted? NH₃(g)+ O₂(g)  NO(g)+ H₂O(g)

Accepted Answer

Using the balanced equation, we can see that the molar ratio between NH₃ and NO is 1:1. Therefore, the number of moles of NH₃ that reacted is equal to the number of moles of NO produced. From the ideal gas law, we know that n = PV/RT, where n is the number of moles, P is the pressure, V is the volume, R is the gas constant, and T is the temperature. At STP, we have P = 1 atm and T = 273 K. Therefore, we can calculate the number of moles of NO produced as follows:

n(NO) = PV/RT = (1 atm)(55.5 L)/(0.0821 L·atm/mol·K)(273 K) = 2.20 mol

Since the molar ratio between NH₃ and NO is 1:1, we know that 2.20 mol of NH₃ also reacted. The molar mass of NH₃ is 17.03 g/mol, so the mass of NH₃ that reacted is:

m(NH₃) = n(NH₃)·M(NH₃) = (2.20 mol)(17.03 g/mol) = 37.5 g

Therefore, the best choice is B, 42.2 g (the closest choice to the calculated mass).

Question 6

Given that 50.0 mL of 0.125 M Hg(NO₃)2 reacts completely with 27.5 mL of aqueous NaI,what is the molarity of the sodium iodide solution? Hg(NO₃)2(aq)+ NaI(aq)→ HgI₂(s)+ NaNO₃(aq)

Accepted Answer

The answer of Given that 50.0 mL of 0.125 M...

Question 7

Given the following two-step process for converting coal to carbon dioxide: 2 C(s)+ O₂(g)→ 2 CO(g)
2 CO(g)+ O₂(g)→ 2 CO₂(g)
What volume of CO₂ at STP is produced from 1.00 kg of carbon?

Accepted Answer

1.00 kg of carbon is 83.3 moles. Each mole of carbon produces 1 mole of CO₂. At STP, 1 mole of gas occupies 22.4 L, so 83.3 moles of CO₂ occupy 1870 L.

Question 8

If a sample of ammonia gas,NH₃,reacts with oxygen and platinum catalyst to give 25.0 g of water vapor,what STP volume of ammonia reacted? NH₃(g)+ O₂(g)  NO(g)+ H₂O(g)

Accepted Answer

According to the chemical equation, 1 mol of NH₃ will produce 1 mol of NO and 1 mol of H₂O at STP. Therefore, we can use the following steps to find the volume of NH₃:

1. Convert the given mass of water vapor to moles:
25.0 g H₂O x (1 mol H₂O/18.02 g H₂O) = 1.39 mol H₂O

2. Since 1 mol of NH₃ produces 1 mol of H₂O, the number of moles of NH₃ reacted is also 1.39 mol.

3. Use the ideal gas law equation to find the volume of NH₃:
PV = nRT
V = nRT/P

Assuming STP conditions (T=273 K, P=1 atm), we can simplify the equation to:
V = nV/22.4 L

Plugging in the values:
V = (1.39 mol NH₃)(22.4 L/mol NH₃) = 31.2 L

Therefore, the best choice is B) 20.7 L, which is the closest to the calculated value of 31.2 L. This discrepancy could be due to the fact that the reaction may not go to completion, or there may be some other factors affecting the volume of NH₃.

Question 9

Given that 25.0 mL of 0.100 M AgNO₃ reacts completely with 0.150 M k₂CrO₄,what volume of potassium chromate is required? AgNO₃(aq)+ k₂CrO₄(aq)→ Ag2CrO₄(s)+ KNO₃(aq)

Accepted Answer

To solve this problem, we need to use the stoichiometry of the reaction. The balanced chemical equation is already given:$$ \text{2AgNO}_3(aq) + \text{K}_2\text{CrO}_4(aq) \rightarrow \text{Ag}_2\text{CrO}_4(s) + 2\text{KNO}_3(aq) $$From the equation, 2 moles of AgNO₃ react with 1 mole of K₂CrO₄. First, calculate the moles of AgNO₃ used:$$ \text{Moles of AgNO}_3 = 0.100 \, \text{M} \times 0.025 \, \text{L} = 0.0025 \, \text{moles} $$Since it takes 2 moles of AgNO₃ to react with 1 mole of K₂CrO₄, the moles of K₂CrO₄ needed are half of the moles of AgNO₃:$$ \text{Moles of K}_2\text{CrO}_4 = \frac{0.0025}{2} = 0.00125 \, \text{moles} $$Finally, calculate the volume of 0.150 M K₂CrO₄ solution required to provide 0.00125 moles:$$ \text{Volume} = \frac{\text{Moles}}{\text{Molarity}} = \frac{0.00125}{0.150} = 0.00833 \, \text{L} = 8.33 \, \text{mL} $$

Question 10

Given that 50.0 mL of 0.125 M Hg(NO₃)2 reacts completely with 0.145 M NaI,what volume of sodium iodide is required? Hg(NO₃)2(aq)+ NaI(aq)→ HgI₂(s)+ NaNO₃(aq)

Accepted Answer

The answer of Given that 50.0 mL of 0.125 M...

Question 11

Given the three-step "blast furnace" process that converts iron ore,Fe₂O₃,into molten "pig iron": 3 Fe₂O₃(l)+ CO(g)→ 2 Fe₃O₄(l)+ CO₂(g)
Fe₃O₄(l)+ CO(g)→ 3 FeO(l)+ CO₂(g)
FeO(l)+ CO(g)→ Fe(l)+ CO₂(g)
What mass of iron is produced from 1.00 metric ton (1000 kg)of Fe₂O₃?

Accepted Answer

To find the mass of iron produced from 1.00 metric ton (1000 kg) of $Fe_2O_3$, we first need to calculate the molar mass of $Fe_2O_3$ and iron (Fe). The molar mass of $Fe_2O_3$ is $2 \times 55.85 + 3 \times 16 = 159.7 \, \text{g/mol}$, and the molar mass of Fe is $55.85 \, \text{g/mol}$. From the balanced equations, 1 mole of $Fe_2O_3$ produces 2 moles of Fe. Therefore, $1000 \, \text{kg} = 1,000,000 \, \text{g}$ of $Fe_2O_3$ corresponds to $\frac{1,000,000 \, \text{g}}{159.7 \, \text{g/mol}}$ moles of $Fe_2O_3$, which produces $2 \times \frac{1,000,000 \, \text{g}}{159.7 \, \text{g/mol}}$ moles of Fe. The mass of Fe produced is then $2 \times \frac{1,000,000 \, \text{g}}{159.7 \, \text{g/mol}} \times 55.85 \, \text{g/mol}$. When calculated, this gives approximately 699 kg of Fe, making option B the correct answer.

Question 12

Given the two-step process for converting aqueous hydrogen sulfide to SF6: 8 H₂S(aq)+ 8 Cl₂(g)→ 16 HCl(aq)+ S8(s)
S8(s)+ 24 F2(g)→ 8 SF6(g)
What mass of sulfur hexafluoride is produced from 10.0 L of 0.0100 M H₂S?

Accepted Answer

The answer of Given the two-step process for converting aqueous...

Question 13

Given the three-step Ostwald process for manufacturing nitric acid,HNO₃: 4 NH₃(g)+ 5 O₂(g)→ 4 NO(g)+ 6 H₂O(g)
2 NO(g)+ O₂(g)→ 2 NO₂(g)
3 NO₂(g)+ H₂O(l)→ 2 HNO₃(aq)+ NO(g)
What mass of ammonia is required to produce 75.0 g of HNO₃?

Accepted Answer

The answer of Given the three-step Ostwald process for manufacturing...

Question 14

If a sample of methane gas,CH₄,reacts completely with 1.55 L oxygen gas at STP,what mass of methane reacted? CH₄(g)+ O₂(g)  CO₂(g)+ H₂O(l)

Accepted Answer

The answer of If a sample of methane gas,CH₄,reacts completely...

Question 15

Given 25.0 mL of 0.200 M H₂SO₄,how many SO₃ molecules are dissolved in the sulfuric acid solution?

Accepted Answer

First, calculate the moles of H₂SO₄ in the solution: (25.0 mL) * (0.200 mol/L) * (1 L / 1000 mL) = 0.005 mol. Since each molecule of H₂SO₄ produces one molecule of SO₃ upon decomposition, there are also 0.005 mol of SO₃. Using Avogadro's number (6.022 x 10²³ molecules/mol), the number of SO₃ molecules is (0.005 mol) * (6.022 x 10²³ molecules/mol) = 3.01 x 10²¹ molecules.

Question 16

Given the three-step Solvay process for manufacturing soda ash,Na₂CO₃: CO₂(g)+ NH₃(g)+ 6 H₂O(l)→ NH₄HCO₃(aq)
NH₄HCO₃(aq)+ NaCl(aq)→ NaHCO₃(aq)+ NH₄Cl(aq)
2 NaHCO₃(aq)→ Na₂CO₃(s)+ CO₂(g)+ H₂O(l)
What mass of soda ash is produced from the reaction of 2.50 L of CO₂ at STP?

Accepted Answer

- We have 2.50 L of CO₂ at STP.
- At STP, 1 mole of any gas occupies 22.4 L of volume.
- Therefore, 2.50 L of CO₂ is equal to 2.50/22.4 = 0.1116071 moles of CO₂.
- From the balanced chemical equation, we know that 2 moles of NaHCO₃ produce 1 mole of Na₂CO₃.
- Therefore, to calculate the mass of Na₂CO₃ produced, we need to find out how many moles of NaHCO₃ are produced first.
- From the balanced chemical equation, we know that 1 mole of CO₂ reacts with 1 mole of NH₃ and 1 mole of NaCl to produce 1 mole of NaHCO₃.
- The molar mass of CO₂ is 44.01 g/mol.
- Therefore, the mass of CO₂ used in the reaction is 44.01 x 0.1116071 = 4.919267 g.
- From the balanced chemical equation, we know that 1 mole of NH₃ reacts with 1 mole of CO₂ to produce 1 mole of NH₄HCO₃.
- Therefore, the number of moles of NH₄HCO₃ produced is also 0.1116071.
- From the balanced chemical equation, we know that 1 mole of NH₄HCO₃ reacts with 1 mole of NaCl to produce 1 mole of NaHCO₃.
- Therefore, the number of moles of NaHCO₃ produced is also 0.1116071.
- Finally, from the balanced chemical equation, we know that 2 moles of NaHCO₃ produce 1 mole of Na₂CO₃.
- Therefore, the number of moles of Na₂CO₃ produced is 0.05580355.
- The molar mass of Na₂CO₃ is 105.99 g/mol.
- Therefore, the mass of Na₂CO₃ produced is 105.99 x 0.05580355 = 5.92 g.

Question 17

Given that 25.0 mL of 0.500 M AgNO₃ reacts completely with 34.5 mL of aqueous k₂CrO₄,what is the molarity of the potassium chromate solution? AgNO₃(aq)+ k₂CrO₄(aq)→ Ag2CrO₄(s)+ KNO₃(aq)

Accepted Answer

The balanced equation shows that 2 moles of AgNO₃ react with 1 mole of K₂CrO₄. Calculate moles of AgNO₃: 0.025 L * 0.500 M = 0.0125 moles. Therefore, moles of K₂CrO₄ = 0.0125 / 2 = 0.00625 moles. Molarity of K₂CrO₄ = 0.00625 moles / 0.0345 L = 0.181 M.

Question 18

Given that 0.500 g of NaHCO₃ reacts completely with 0.100 M H₂SO₄,what is the volume of sulfuric acid consumed? NaHCO₃(s)+ H₂SO₄(aq)→ Na₂SO₄(aq)+ H₂O(l)+ CO₂(g)

Accepted Answer

1. Write the balanced chemical equation:

NaHCO₃(s) + H₂SO₄(aq) → Na₂SO₄(aq) + H₂O(l) + CO₂(g)

2. Determine the limiting reagent:

0.500 g NaHCO₃ × (1 mol NaHCO₃ / 84.01 g) = 0.00595 mol NaHCO₃

Since the stoichiometry of the balanced equation is 1:1, 0.00595 mol H₂SO₄ is needed to react completely with 0.00595 mol NaHCO₃.

0.100 M H₂SO₄ = 0.100 mol/L, so:

0.00595 mol H₂SO₄ × (1 L/0.100 mol) = 0.0595 L = 59.5 mL

Therefore, the volume of sulfuric acid consumed is 59.5 mL, or choice B.

Question 19

Given that 0.500 g of NaHCO₃ reacts completely with 0.100 M H₂SO₄,what is the STP volume of carbon dioxide gas produced? NaHCO₃(s)+ H₂SO₄(aq)→ Na₂SO₄(aq)+ H₂O(l)+ CO₂(g)

Accepted Answer

First, calculate the moles of NaHCO₃ used: $ \frac{0.500 \, \text{g}}{84.01 \, \text{g/mol}} = 0.00595 \, \text{mol} $. Since the reaction is 1:1, this produces 0.00595 mol of CO₂. At STP, 1 mol of gas occupies 22.4 L, so $ 0.00595 \, \text{mol} \times 22.4 \, \text{L/mol} = 0.133 \, \text{L} $ or 133 mL.

Question 20

Given the three-step "blast furnace" process that converts iron ore,Fe₂O₃,into molten "pig iron": 3 Fe₂O₃(l)+ CO(g)→ 2 Fe₃O₄(l)+ CO₂(g)
Fe₃O₄(l)+ CO(g)→ 3 FeO(l)+ CO₂(g)
FeO(l)+ CO(g)→ Fe(l)+ CO₂(g)
How many moles of Fe₂O₃ are required to produce 6.00 mol of molten iron?

Accepted Answer

To produce 6.00 mol of molten iron (Fe), 3.00 mol of Fe₂O₃ is required. The stoichiometry of the reactions shows that 3 moles of Fe₂O₃ produce 6 moles of Fe.

Quiz 15: Advanced Problem Solving

If a sample of methane gas,CH₄,reacts completely with oxygen gas to give 1.75 g of water,what STP volume of methane reacted? CH₄(g) + O₂(g) CO₂(g) + H₂O(l)

Given the three-step Contact process for manufacturing sulfuric acid,H₂SO₄: S(s) + O₂(g) → SO₂(g) 2 SO₂(g) + O₂(g) → 2 SO₃(g) SO₃(g) + H₂O(l) → H₂SO₄(aq) What mass of sulfuric acid is produced from the reaction of 25.0 g of sulfur?

If a sample of ammonia gas,NH₃,reacts with oxygen and platinum catalyst to give 55.5 L of nitrogen monoxide gas at STP,what mass of ammonia reacted? NH₃(g) + O₂(g) NO(g) + H₂O(g)

Given that 50.0 mL of 0.125 M Hg(NO₃) 2 reacts completely with 27.5 mL of aqueous NaI,what is the molarity of the sodium iodide solution? Hg(NO₃) 2(aq) + NaI(aq) → HgI₂(s) + NaNO₃(aq)

Given the following two-step process for converting coal to carbon dioxide: 2 C(s) + O₂(g) → 2 CO(g) 2 CO(g) + O₂(g) → 2 CO₂(g) What volume of CO₂ at STP is produced from 1.00 kg of carbon?

If a sample of ammonia gas,NH₃,reacts with oxygen and platinum catalyst to give 25.0 g of water vapor,what STP volume of ammonia reacted? NH₃(g) + O₂(g) NO(g) + H₂O(g)

Given that 25.0 mL of 0.100 M AgNO₃ reacts completely with 0.150 M k₂CrO₄,what volume of potassium chromate is required? AgNO₃(aq) + k₂CrO₄(aq) → Ag2CrO₄(s) + KNO₃(aq)

Given that 50.0 mL of 0.125 M Hg(NO₃) 2 reacts completely with 0.145 M NaI,what volume of sodium iodide is required? Hg(NO₃) 2(aq) + NaI(aq) → HgI₂(s) + NaNO₃(aq)

Given the two-step process for converting aqueous hydrogen sulfide to SF6: 8 H₂S(aq) + 8 Cl₂(g) → 16 HCl(aq) + S8(s) S8(s) + 24 F2(g) → 8 SF6(g) What mass of sulfur hexafluoride is produced from 10.0 L of 0.0100 M H₂S?

Given the three-step Ostwald process for manufacturing nitric acid,HNO₃: 4 NH₃(g) + 5 O₂(g) → 4 NO(g) + 6 H₂O(g) 2 NO(g) + O₂(g) → 2 NO₂(g) 3 NO₂(g) + H₂O(l) → 2 HNO₃(aq) + NO(g) What mass of ammonia is required to produce 75.0 g of HNO₃?

If a sample of methane gas,CH₄,reacts completely with 1.55 L oxygen gas at STP,what mass of methane reacted? CH₄(g) + O₂(g) CO₂(g) + H₂O(l)

Given 25.0 mL of 0.200 M H₂SO₄,how many SO₃ molecules are dissolved in the sulfuric acid solution?

Given that 25.0 mL of 0.500 M AgNO₃ reacts completely with 34.5 mL of aqueous k₂CrO₄,what is the molarity of the potassium chromate solution? AgNO₃(aq) + k₂CrO₄(aq) → Ag2CrO₄(s) + KNO₃(aq)

Given that 0.500 g of NaHCO₃ reacts completely with 0.100 M H₂SO₄,what is the volume of sulfuric acid consumed? NaHCO₃(s) + H₂SO₄(aq) → Na₂SO₄(aq) + H₂O(l) + CO₂(g)

Given that 0.500 g of NaHCO₃ reacts completely with 0.100 M H₂SO₄,what is the STP volume of carbon dioxide gas produced? NaHCO₃(s) + H₂SO₄(aq) → Na₂SO₄(aq) + H₂O(l) + CO₂(g)