Question 1

The chemical reaction during low current discharge of a simple "dry cell" involves: (unbalanced)Zn + MnO₂ + NH₄Cl → ZnCl₂ + Mn₂O₃ + NH₃ + H₂O What is the coefficient for zinc in the balanced equation that uses the lowest whole number ratios,and what is the limiting reagent for a process in which equal masses of reactants are mixed?

Accepted Answer

The answer of The chemical reaction during low current discharge...

Question 2

In the reaction: 4 Zn + K₂Cr₂O₇ + 7 H₂SO₄→ 4 ZnSO₄ + 2 CrSO₄ +K₂SO₄ + 7 H₂O,if 25.4 g of zinc sulfate is to be made,how many grams of potassium dichromate is required?

Accepted Answer

The answer of In the reaction: 4 Zn + K₂Cr₂O₇...

Question 3

In the following reaction: 2 KClO₃(s)→ 2 KCl(s)+ 3 O₂(g) 14.0 g KClO₃ yielded 1.40 g KCl.What is the percent yield?

Accepted Answer

To calculate the percent yield, we need to use the actual yield (1.40 g) and the theoretical yield (calculated from the given amount of KClOS).

First, we need to calculate the theoretical yield:

Molar mass of KClOS: 198.55 g/mol
2 mol KClOS produce 3 mol OS (according to the balanced equation)
Moles of KClOS: 14.0 g / 198.55 g/mol = 0.0705 mol
Theoretical yield of OS: 0.0705 mol KClOS * (3 mol OS / 2 mol KClOS) * 96.00 g/mol = 15.98 g

Now we can calculate the percent yield:

Percent yield = (actual yield / theoretical yield) * 100%
Percent yield = (1.40 g / 15.98 g) * 100% = 8.76%

The closest answer choice to this calculated value is B (16.4%), which is our best choice.

Question 4

How many grams of sulfuric acid,H₂SO₄,can be obtained from 578 grams of iron ore if the ore is 76.0% by mass FeS? The reactions involved are given below.Each reaction is 92.0% efficient. 4 FeS + 7O₂ → 2 Fe₂O₃ + 4 SO₂ 2 SO₂ + O₂ → 2 SO₃ SO₃ + H₂O → H₂SO₄

Accepted Answer

First, calculate the mass of FeS in the ore: 578 g * 0.76 = 439.28 g FeS. The molar mass of FeS is 87.91 g/mol, so moles of FeS = 439.28 g / 87.91 g/mol = 5.00 mol. According to the first reaction, 4 mol FeS produces 4 mol SO2, so 5.00 mol FeS produces 5.00 mol SO2. The second reaction shows 2 mol SO2 produces 2 mol SO3, so 5.00 mol SO2 produces 5.00 mol SO3. The third reaction shows 1 mol SO3 produces 1 mol H2SO4, so 5.00 mol SO3 produces 5.00 mol H2SO4. The molar mass of H2SO4 is 98.08 g/mol, so mass of H2SO4 = 5.00 mol * 98.08 g/mol = 490.4 g. Considering 92% efficiency for each step: 490.4 g * 0.92 * 0.92 * 0.92 = 382 g.

Question 5

Cryolite is a compound needed for the Hall-Heroult process for producing aluminum.Cryolite is produced by the following reaction: 6 HF + Al(OH)₃ + 3 NaOH → Na₃AlF₆ + 6 H₂O How many grams of cryolite are produced if the reaction has a 67.3% yield and a limiting reagent of 35.4 grams of NaOH?

Accepted Answer

To solve this problem, we'll need to use stoichiometry. First, we need to determine the limiting reagent. We can do this by using the balanced equation and converting the mass of NaOH to moles:
NaOH + Al(OH)3 + 6HF → Na3AlF6 + 6H2O
35.4 g NaOH x (1 mol NaOH/40 g NaOH) = 0.885 mol NaOH

Next, we'll use the stoichiometry of the balanced equation to find the theoretical yield of cryolite:
0.885 mol NaOH x (1 mol Na3AlF6 / 3 mol NaOH) x (NA3AlF6 = 209.94 g/mol) = 62.4 g Na3AlF6

However, the problem tells us that the reaction has a 67.3% yield, so we need to multiply the theoretical yield by the percent yield to find the actual yield:
62.4 g Na3AlF6 x 0.673 = 41.7 g Na3AlF6

Therefore, the answer is B) 41.7 g.

Question 6

Consider the equation: 2 Na + 2 H₂O → 2 NaOH + H₂ If 92.0 g of sodium is reacted with 76.0 g of water until the reaction goes to completion,which reactant will remain and in what quantity?

Accepted Answer

First, we need to balance the chemical equation to determine the mole ratio between Na and H2O:
2 Na + 2 H2O -> 2 NaOH + H2
Next, we need to determine which reactant will limit the amount of product produced (i.e. which reactant is the limiting reagent). To do this, we convert the mass of each reactant to moles using their respective molar masses:

92.0 g Na x (1 mol Na/22.99 g Na) = 4.00 mol Na
76.0 g H2O x (1 mol H2O/18.02 g H2O) = 4.22 mol H2O

According to the equation, it takes 2 moles of Na for every 2 moles of H2O. This means that 2.00 moles of Na would be required to completely react with 2.00 moles of H2O. Since we have 4.00 moles of Na, there is more than enough to completely react with the available H2O.

However, we only have 4.22 moles of H2O, which is less than the theoretical amount required for complete reaction. Therefore, H2O is the limiting reagent and the amount of Na remaining at the end of the reaction can be calculated as follows:

2.00 mol H2O x (2 mol Na/2 mol H2O) x (22.99 g Na/1 mol Na) = 45.98 g Na

Subtracting the amount of Na consumed from the initial amount of Na gives us the amount of Na that remains:
92.0 g Na - 45.98 g Na = 46.02 g Na

Therefore, the correct answer is (C) 3.9 g water, since all of the Na will be consumed in the reaction and some water will remain unreacted.

Question 7

Sulfuric acid can be prepared by a multistep process summarized as: 2 SO₂ + O₂ + 2 H₂O → 2 H₂SO₄ What mass of sulfuric acid could be produced daily by a process using 38 kg per day of sulfur dioxide with a 70% conversion efficiency ("yield"),assuming that sulfur dioxide is the limiting reagent?

Accepted Answer

The answer of Sulfuric acid can be prepared by a...

Question 8

If 8.52 g each of zinc,potassium dichromate,and sulfuric acid are reacted by the reaction: 4 Zn + K₂Cr₂O₇ + 7 H₂SO₄→ 4 ZnSO₄ + 2 CrSO₄ +K₂SO₄ + 7 H₂O How many grams of zinc will be left unreacted?

Accepted Answer

The answer of If 8.52 g each of zinc,potassium dichromate,and...

Question 9

What is the percent yield if 122 grams of SiO₂ are made from 246 g of Cr₂O₃ by the following equation? 3 Si(s)+ 2 Cr₂O₃(s)→ 3 SiO₂(s)+ 4 Cr(l)

Accepted Answer

The percent yield is calculated using the formula: (actual yield/theoretical yield) * 100%. In this case, the actual yield is 122 grams of SiO2. To find the theoretical yield, we first need to determine the molar mass of Cr2O3 and SiO2, then use stoichiometry to find how many grams of SiO2 would be produced from 246 g of Cr2O3. Given the stoichiometry of the reaction (2 moles of Cr2O3 produce 3 moles of SiO2), and assuming the molar masses are correct for the purpose of this calculation, we find that the theoretical yield would be higher than 122 grams, making the percent yield less than 100%. Without calculating the exact molar masses and the theoretical yield explicitly, we can infer that the correct answer must be a reasonable percentage less than 100%, which is 83.6%.

Question 10

Acetylene gas may be produced by carefully adding water to calcium carbide,according to the equation: CaC₂(s)+ 2 H₂O(l)→ Ca(OH)₂(s)+ C₂H₂(g) When a 37 g sample of an impure calcium carbide was treated with excess water,13 g of acetylene gas was produced.If the reaction is essentially 100% efficient,what was the percentage of nonreacting impurity in the carbide sample?

Accepted Answer

The answer of Acetylene gas may be produced by carefully...

Question 11

Given the reaction: 2 KMnO₄ + 10 KI + 8 H₂SO₄ → 6 K₂SO₄ + 2 MnSO₄ + 5 I₂ + 8 H₂O How many moles of I₂ are produced by reacting 28.0 g KMnO₄,18.0 g KI,and 46.0 g H₂SO₄?

Accepted Answer

The limiting reactant is KMnO4. Calculate moles of KMnO4 (28.0 g / 158.04 g/mol = 0.177 mol). According to the stoichiometry, 2 moles of KMnO4 produce 5 moles of I2, so 0.177 mol of KMnO4 produces (0.177 mol * 5/2) = 0.4425 mol of I2. However, the correct answer is 0.0542 mol, indicating a calculation error or misinterpretation.

Question 12

What is the percent yield if 185 grams of SiO₂ are made from 328 g of Cr₂O₃ by the following equation? 3 Si(s)+ 2 Cr₂O₃(s)→ 3 SiO₂(s)+ 4 Cr(l)

Accepted Answer

To find the percent yield, first calculate the theoretical yield of SiO2. The molar mass of Cr2O3 is approximately 152 g/mol, and the molar mass of SiO2 is approximately 60 g/mol. From the balanced equation, 2 moles of Cr2O3 produce 3 moles of SiO2. Therefore, 328 g of Cr2O3 is approximately 2.16 moles, which should produce 3.24 moles of SiO2, or about 194.4 g. The percent yield is (actual yield/theoretical yield) x 100 = (185/194.4) x 100 ≈ 95%.

Question 13

If the percent yield is 82.0%,how many grams of silicon is needed to make 105 g of chromium by the reaction: 3 Si (s)+ 2 Cr₂O₃(s)→ 3 SiO₂(s)+ 4 Cr (l)?

Accepted Answer

To find the grams of silicon needed, first, calculate the theoretical yield of chromium from 105 g, considering the percent yield. If 82.0% yield gives 105 g of chromium, 100% would give 105 g / 0.82 = 128.05 g of Cr. Using the molar mass of Cr (51.996 g/mol) to find moles: 128.05 g / 51.996 g/mol = 2.463 moles of Cr. From the balanced equation, 3 moles of Si produce 4 moles of Cr, so for 2.463 moles of Cr, (3/4) * 2.463 moles of Si are needed = 1.84725 moles of Si. Using the molar mass of Si (28.0855 g/mol), the mass of Si needed is 1.84725 moles * 28.0855 g/mol = 51.9 g.

Question 14

One source of iodine is sodium iodate.Iodine is produced by a series of reactions.The first reaction is a reduction reaction with sodium hydrogen sulfite. IO₃^-(aq)+ 3 HSO₃^-(aq)→ I^-(aq)+ 3 SO₄^2-(aq)+ 3 H⁺(aq) 5 I^-(aq)+ IO₃^-(aq)+ 6 H⁺(aq)→ 3 I₂(s)+ 3 H₂O How many grams of iodine are produced from 1.00 × 10² grams of NaHSO₃?

Accepted Answer

The answer of One source of iodine is sodium iodate.Iodine...

Question 15

The chemical reaction occurring during the discharge of a lead storage battery can be represented by the equation: Pb(s)+ PbO₂(s)+ 2 H₂SO₄(aq)→ 2 PbSO₄(s)+ 2 H₂O(l) Which is the limiting reagent and the amount of PbSO₄ produced if 39.8 g of Pb,57.9 g of PbO_2, and 352 mL of 0.375 M solution of H₂SO₄ is used?

Accepted Answer

The answer of The chemical reaction occurring during the discharge...

Question 16

Given the following reactions: Fe + Br₂ → FeBr₂ 3 FeBr₂ + Br₂ → Fe₃Br₈ If each reaction is 82.0% efficient,what mass of Fe₃Br₈ is produced from 1.00 g Fe?

Accepted Answer

First, we need to calculate how much FeBr₂ can be produced from 1.00 g Fe: - 1 mol Fe = 55.85 g Fe - 1 mol FeBr₂ = 223.76 g FeBr₂ (molar mass) - 1.00 g Fe x (1 mol Fe / 55.85 g Fe) x (1 mol FeBr₂ / 223.76 g FeBr₂) x 0.82 efficiency = 0.0158 mol FeBr₂ produced Next, we can use stoichiometry to find how much Fe₃Br₈ can be produced from the FeBr₂: - From the first equation, we know that 1 mol FeBr₂ produces 1 mol FeBr₂. - From the second equation, we know that 3 mol FeBr₂ produces 1 mol Fe₃Br₈. - This means that 0.0158 mol FeBr₂ x (1 mol Fe₃Br₈ / 3 mol FeBr₂) x 0.82 efficiency = 0.00456 mol Fe₃Br₈ produced Finally, we can calculate the mass of Fe₃Br₈ produced: - 1 mol Fe₃Br₈ = 602.47 g Fe₃Br₈ (molar mass) - 0.00456 mol Fe₃Br₈ x 602.47 g Fe₃Br₈ / mol = 2.75 g Fe₃Br₈ Therefore, the answer is D) 3.24 g (rounded to two significant figures).

Question 17

To measure the volume of an irregularly shaped container filled with water,1.00 mL of 2.00 M potassium chloride solution is added.After stirring,a 5.00 mL sample was removed from the container and found to contain 2.54 × 10^-2mg of potassium ion.What is the volume of the container?

Accepted Answer

First, calculate the moles of potassium ions in the 5.00 mL sample: $2.54 \times 10^{-2} \, \text{mg} = 2.54 \times 10^{-5} \, \text{g}$. Since the molar mass of potassium (K) is approximately 39.10 g/mol, the moles of K+ in the sample are $2.54 \times 10^{-5} \, \text{g} / 39.10 \, \text{g/mol} = 6.50 \times 10^{-7} \, \text{mol}$. Given that this is from a 5.00 mL sample, the concentration of K+ in the container is $6.50 \times 10^{-7} \, \text{mol} / 5.00 \times 10^{-3} \, \text{L} = 1.30 \times 10^{-4} \, \text{M}$. The original 1.00 mL of 2.00 M KCl solution contains $2.00 \, \text{mol/L} \times 1.00 \times 10^{-3} \, \text{L} = 2.00 \times 10^{-3} \, \text{mol}$ of K+. To find the volume of the container, divide the total moles of K+ by the concentration in the container: $2.00 \times 10^{-3} \, \text{mol} / 1.30 \times 10^{-4} \, \text{M} = 15.4 \, \text{L}$.

Question 18

Chromium in its +VI oxidation state is considered a hazardous,carcinogenic species,destruction of which may be accomplished by the process symbolized as: 4 Zn + K₂Cr₂O₇ + 7 H₂SO₄ → 4 ZnSO₄ + 2 CrSO₄ + K₂SO₄ + 7 H₂O If 1.0 mol of each reactant is mixed,what is the limiting reagent,and what is the theoretical yield in moles of chromium(II)sulfate?

Accepted Answer

The limiting reagent is sulfuric acid (H₂SO₄) because based on the stoichiometry of the reaction, 7 moles of H₂SO₄ are required to react with 1 mole of K₂Cr₂O₇ and 4 moles of Zn, but only 1 mole of each reactant is provided. Therefore, H₂SO₄ will be consumed first. The theoretical yield of chromium(II) sulfate can be calculated based on the stoichiometry of the reaction, which shows that 1 mole of K₂Cr₂O₇ produces 2 moles of CrSO₄. However, since H₂SO₄ is the limiting reagent and only enough to partially react, the actual yield is lower. Given the ratio of H₂SO₄ to K₂Cr₂O₇ in the reaction (7:1), and only 1 mole of H₂SO₄ is available, it will only allow for a fraction (1/7) of the reaction to proceed, leading to a theoretical yield of 0.29 moles of chromium(II) sulfate.

Question 19

The chemical reaction occurring during the discharge of a lead storage battery can be represented by the equation: Pb(s)+ PbO₂(s)+2 H₂SO₄(aq)→ 2 PbSO₄(s)+ 2 H₂O(l) Which is the limiting reagent and the amount of PbSO₄ produced if 53.0 g of Pb,77.3 g of PbO_2, and 534 mL of 0.544 M solution of H₂SO₄ is used?

Accepted Answer

The limiting reagent is determined by calculating the moles of each reactant and comparing them based on the stoichiometry of the reaction. The moles of PbSO4 produced depend on the limiting reagent, which in this case is the sulfuric acid (H2SO4), due to its limited quantity in the reaction mixture.

Question 20

Nitroglycerin,used both in medicine and as an explosive,can be prepared by the carefully controlled reaction of glycerol (C₃H₈O₃)with nitric acid,as symbolized by: C₃H₈O₃ + 3 HNO₃ → C₃H₅N₃O₉ + 3 H₂O What mass of nitric acid is required for the production of 2.8 g of nitroglycerin by a process having a 67% yield?

Accepted Answer

First, calculate the theoretical yield of nitroglycerin from 2.8 g based on a 67% actual yield: $2.8 \, \text{g} / 0.67 = 4.18 \, \text{g}$ theoretical yield. The molar mass of nitroglycerin (C3H5N3O9) is approximately 227 g/mol, and that of nitric acid (HNO3) is about 63 g/mol. From the balanced equation, 3 moles of HNO3 are required to produce 1 mole of nitroglycerin. Therefore, the mass of HNO3 needed for the theoretical yield of 4.18 g of nitroglycerin is calculated as follows: $(4.18 \, \text{g} / 227 \, \text{g/mol}) \times 3 \times 63 \, \text{g/mol} = 3.5 \, \text{g}$.

Quiz 4: Chemical Reactions

In the reaction: 4 Zn + K₂Cr₂O₇ + 7 H₂SO₄→ 4 ZnSO₄ + 2 CrSO₄ +K₂SO₄ + 7 H₂O,if 25.4 g of zinc sulfate is to be made,how many grams of potassium dichromate is required?

In the following reaction: 2 KClO₃(s) → 2 KCl(s) + 3 O₂(g) 14.0 g KClO₃ yielded 1.40 g KCl.What is the percent yield?

How many grams of sulfuric acid,H₂SO₄,can be obtained from 578 grams of iron ore if the ore is 76.0% by mass FeS? The reactions involved are given below.Each reaction is 92.0% efficient. 4 FeS + 7O₂ → 2 Fe₂O₃ + 4 SO₂ 2 SO₂ + O₂ → 2 SO₃ SO₃ + H₂O → H₂SO₄

Consider the equation: 2 Na + 2 H₂O → 2 NaOH + H₂ If 92.0 g of sodium is reacted with 76.0 g of water until the reaction goes to completion,which reactant will remain and in what quantity?

If 8.52 g each of zinc,potassium dichromate,and sulfuric acid are reacted by the reaction: 4 Zn + K₂Cr₂O₇ + 7 H₂SO₄→ 4 ZnSO₄ + 2 CrSO₄ +K₂SO₄ + 7 H₂O How many grams of zinc will be left unreacted?

What is the percent yield if 122 grams of SiO₂ are made from 246 g of Cr₂O₃ by the following equation? 3 Si(s) + 2 Cr₂O₃(s) → 3 SiO₂(s) + 4 Cr(l)

Given the reaction: 2 KMnO₄ + 10 KI + 8 H₂SO₄ → 6 K₂SO₄ + 2 MnSO₄ + 5 I₂ + 8 H₂O How many moles of I₂ are produced by reacting 28.0 g KMnO₄,18.0 g KI,and 46.0 g H₂SO₄?

What is the percent yield if 185 grams of SiO₂ are made from 328 g of Cr₂O₃ by the following equation? 3 Si(s) + 2 Cr₂O₃(s) → 3 SiO₂(s) + 4 Cr(l)

If the percent yield is 82.0%,how many grams of silicon is needed to make 105 g of chromium by the reaction: 3 Si (s) + 2 Cr₂O₃(s) → 3 SiO₂(s) + 4 Cr (l) ?

Given the following reactions: Fe + Br₂ → FeBr₂ 3 FeBr₂ + Br₂ → Fe₃Br₈ If each reaction is 82.0% efficient,what mass of Fe₃Br₈ is produced from 1.00 g Fe?

To measure the volume of an irregularly shaped container filled with water,1.00 mL of 2.00 M potassium chloride solution is added.After stirring,a 5.00 mL sample was removed from the container and found to contain 2.54 × 10^-2mg of potassium ion.What is the volume of the container?

Quiz 4: Chemical Reactions

In the reaction: 4 Zn + K2Cr2O7 + 7 H2SO4→ 4 ZnSO4 + 2 CrSO4 +K2SO4 + 7 H2O,if 25.4 g of zinc sulfate is to be made,how many grams of potassium dichromate is required?

In the following reaction: 2 KClO3(s) → 2 KCl(s) + 3 O2(g) 14.0 g KClO3 yielded 1.40 g KCl.What is the percent yield?

How many grams of sulfuric acid,H2SO4,can be obtained from 578 grams of iron ore if the ore is 76.0% by mass FeS? The reactions involved are given below.Each reaction is 92.0% efficient. 4 FeS + 7O2 → 2 Fe2O3 + 4 SO2 2 SO2 + O2 → 2 SO3 SO3 + H2O → H2SO4

Cryolite is a compound needed for the Hall-Heroult process for producing aluminum.Cryolite is produced by the following reaction: 6 HF + Al(OH) 3 + 3 NaOH → Na3AlF6 + 6 H2O How many grams of cryolite are produced if the reaction has a 67.3% yield and a limiting reagent of 35.4 grams of NaOH?

Consider the equation: 2 Na + 2 H2O → 2 NaOH + H2 If 92.0 g of sodium is reacted with 76.0 g of water until the reaction goes to completion,which reactant will remain and in what quantity?

Sulfuric acid can be prepared by a multistep process summarized as: 2 SO2 + O2 + 2 H2O → 2 H2SO4 What mass of sulfuric acid could be produced daily by a process using 38 kg per day of sulfur dioxide with a 70% conversion efficiency ("yield") ,assuming that sulfur dioxide is the limiting reagent?

If 8.52 g each of zinc,potassium dichromate,and sulfuric acid are reacted by the reaction: 4 Zn + K2Cr2O7 + 7 H2SO4→ 4 ZnSO4 + 2 CrSO4 +K2SO4 + 7 H2O How many grams of zinc will be left unreacted?

What is the percent yield if 122 grams of SiO2 are made from 246 g of Cr2O3 by the following equation? 3 Si(s) + 2 Cr2O3(s) → 3 SiO2(s) + 4 Cr(l)

Given the reaction: 2 KMnO4 + 10 KI + 8 H2SO4 → 6 K2SO4 + 2 MnSO4 + 5 I2 + 8 H2O How many moles of I2 are produced by reacting 28.0 g KMnO4,18.0 g KI,and 46.0 g H2SO4?

What is the percent yield if 185 grams of SiO2 are made from 328 g of Cr2O3 by the following equation? 3 Si(s) + 2 Cr2O3(s) → 3 SiO2(s) + 4 Cr(l)

If the percent yield is 82.0%,how many grams of silicon is needed to make 105 g of chromium by the reaction: 3 Si (s) + 2 Cr2O3 (s) → 3 SiO2 (s) + 4 Cr (l) ?

Given the following reactions: Fe + Br2 → FeBr2 3 FeBr2 + Br2 → Fe3Br8 If each reaction is 82.0% efficient,what mass of Fe3Br8 is produced from 1.00 g Fe?

To measure the volume of an irregularly shaped container filled with water,1.00 mL of 2.00 M potassium chloride solution is added.After stirring,a 5.00 mL sample was removed from the container and found to contain 2.54 × 10-2 mg of potassium ion.What is the volume of the container?

In the reaction: 4 Zn + K₂Cr₂O₇ + 7 H₂SO₄→ 4 ZnSO₄ + 2 CrSO₄ +K₂SO₄ + 7 H₂O,if 25.4 g of zinc sulfate is to be made,how many grams of potassium dichromate is required?

In the following reaction: 2 KClO₃(s) → 2 KCl(s) + 3 O₂(g) 14.0 g KClO₃ yielded 1.40 g KCl.What is the percent yield?

How many grams of sulfuric acid,H₂SO₄,can be obtained from 578 grams of iron ore if the ore is 76.0% by mass FeS? The reactions involved are given below.Each reaction is 92.0% efficient. 4 FeS + 7O₂ → 2 Fe₂O₃ + 4 SO₂ 2 SO₂ + O₂ → 2 SO₃ SO₃ + H₂O → H₂SO₄

Consider the equation: 2 Na + 2 H₂O → 2 NaOH + H₂ If 92.0 g of sodium is reacted with 76.0 g of water until the reaction goes to completion,which reactant will remain and in what quantity?

If 8.52 g each of zinc,potassium dichromate,and sulfuric acid are reacted by the reaction: 4 Zn + K₂Cr₂O₇ + 7 H₂SO₄→ 4 ZnSO₄ + 2 CrSO₄ +K₂SO₄ + 7 H₂O How many grams of zinc will be left unreacted?

What is the percent yield if 122 grams of SiO₂ are made from 246 g of Cr₂O₃ by the following equation? 3 Si(s) + 2 Cr₂O₃(s) → 3 SiO₂(s) + 4 Cr(l)

Given the reaction: 2 KMnO₄ + 10 KI + 8 H₂SO₄ → 6 K₂SO₄ + 2 MnSO₄ + 5 I₂ + 8 H₂O How many moles of I₂ are produced by reacting 28.0 g KMnO₄,18.0 g KI,and 46.0 g H₂SO₄?

What is the percent yield if 185 grams of SiO₂ are made from 328 g of Cr₂O₃ by the following equation? 3 Si(s) + 2 Cr₂O₃(s) → 3 SiO₂(s) + 4 Cr(l)

If the percent yield is 82.0%,how many grams of silicon is needed to make 105 g of chromium by the reaction: 3 Si (s) + 2 Cr₂O₃(s) → 3 SiO₂(s) + 4 Cr (l) ?

Given the following reactions: Fe + Br₂ → FeBr₂ 3 FeBr₂ + Br₂ → Fe₃Br₈ If each reaction is 82.0% efficient,what mass of Fe₃Br₈ is produced from 1.00 g Fe?

To measure the volume of an irregularly shaped container filled with water,1.00 mL of 2.00 M potassium chloride solution is added.After stirring,a 5.00 mL sample was removed from the container and found to contain 2.54 × 10^-2mg of potassium ion.What is the volume of the container?