Question 1:

The correct equation for percentage yield is:

A. percentage yield = (actual mass of product / maximum theoretical mass of product) × 100

This compares the actual amount obtained from the experiment to the maximum possible amount calculated from the stoichiometry, then multiplies by 100 to express it as a percentage.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 2:

To find the percentage yield, use the formula:

 Plug in the values.

• Actual mass = 43.2 g

• Theoretical mass = 52.0 g

Rounded to one decimal place, this gives 83.1%.

So the correct answer is:

C. 83.1%

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 3:

The correct answer is:

D. all of the above

All three are valid reasons for obtaining less aspirin than the theoretical maximum:

• A. The reaction may not have gone to completion – Many reactions are reversible or reach equilibrium, so not all reactants are converted to product.

• B. Some aspirin may have been lost during separation – Practical techniques like filtration, washing, or recrystallization often result in mechanical losses.

• C. Some of the salicylic acid may have reacted to produce another product – Side reactions can occur, consuming some of the starting material and forming unwanted by-products.

Since all of these contribute to a lower actual yield, D is the best answer.

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 4:

To find the percentage yield, use the formula:

Plug in the values.

• Actual mass of aspirin = 12.3 g

• Theoretical mass of aspirin = 18.0 g

Rounded to one decimal place, this gives 68.3%.

So the correct answer is:

D. 68.3%

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 5:

To solve this, we need to calculate the molar mass (mass of 1 mole) of mercury(II)oxide (HgO) and then find the number of moles in 21.7 g.

Step 1: Calculate the molar mass of HgO.

From the periodic table:

• Hg = 201

• O = 16

  So the mass of 1 mole of HgO is 217 g.

Step 2: Calculate the number of moles in 21.7 g.

Matching the table:

• Mass of 1 mole of HgO = 217 g

• Number of moles in 21.7 g = 0.1

So the correct option is:

A. 217 / 0.1

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 6:

To solve this, we need to use the balanced equation and stoichiometry to find the theoretical (maximum possible) mass of mercury (Hg), then calculate the percentage yield.

Step 1: Find moles of HgO used.

From the previous question:

• Moles of HgO = 0.1 mol

Step 2: Use the mole ratio from the balanced equation.

The ratio of HgO : Hg is 2 : 2, which simplifies to 1 : 1.
So, moles of Hg produced = moles of HgO used = 0.1 mol

Step 3: Calculate the maximum possible mass of Hg.

Molar mass of Hg (from periodic table) = 201 g/mol

So the maximum possible mass = 20.1 g.

Step 4: Calculate the percentage yield.

Actual mass obtained = 9.0 g
Theoretical mass = 20.1 g

Matching the table:

• Maximum possible mass of Hg = 20.1 g

• % yield = 44.8%

So the correct answer is:

C. 20.1 / 44.8

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 7:

To solve this, we calculate the molar mass of calcium carbonate (CaCO₃) and then find the number of moles in 50 g.

Step 1: Calculate the molar mass of CaCO₃.

From the periodic table:

• Ca = 40 g/mol

• C = 12 g/mol

• O = 16 g/mol (× 3 = 48 g/mol)

So the molar mass of CaCO₃ is 100 g.

Step 2: Calculate the number of moles in 50 g.

Matching the table:

• Molar mass of CaCO₃ = 100 g

• Number of moles in 50 g = 0.5

So the correct answer is:

D. 100 / 0.5

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 8:

To find the mass of calcium oxide (CaO) obtained with a 40% yield, follow these steps:

Step 1: Find the theoretical moles of CaCO₃.

From the previous question:
Moles of CaCO₃ = 0.5 mol

Step 2: Use the mole ratio from the balanced equation.

The ratio is 1 : 1, so:
Theoretical moles of CaO = 0.5 mol

Step 3: Calculate the theoretical mass of CaO.

Molar mass of CaO = Ca (40) + O (16) = 56 g/mol

Step 4: Apply the 40% yield.

Actual mass = Theoretical mass × yield / 100

Actual mass=28.0×40/100=11.2 g

So the correct answer is:

A. 11.2 g

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 9:

To find the maximum possible yield (theoretical yield) of ammonia, we use stoichiometry based on the limiting reactant. Since nitrogen is the reactant with a given mass and hydrogen is in excess, nitrogen is the limiting reactant.

Step 1: Calculate moles of N₂.

• Molar mass of N₂ = 14 × 2 = 28 g/mol = 28 kg/kmol (using kg for consistency)

• Mass of N₂ = 56 kg

Step 2: Use the mole ratio from the balanced equation.

From the equation:
1 mol N₂ → 2 mol NH₃
So 2 kmol N₂ → 2 × 2 = 4 kmol NH₃

Step 3: Calculate the theoretical mass of NH₃.

• Molar mass of NH₃ = N (14) + H (1×3) = 17 g/mol = 17 kg/kmol

So the maximum possible yield is:

C. 68 kg

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.

Question 10:

To find the percentage yield, use the formula:

Step 1: Identify the values.

• Actual mass of NH₃ produced = 51 kg

• Theoretical (maximum possible) mass of NH₃ = 68 kg (from the previous question)

Step 2: Plug into the formula.

So the correct answer is:

B. 75%

*These A.I. responses have been individually checked to ensure they match the accepted answer, but explanations may still be incorrect. Responses may give guidance but the A.I. might not be able to answer the question! This is particularly the case for questions based on diagrams, which the A.I. typically cannot interpret.
Grade Gorilla uses Gemini, Deepseek and a range of other A.I. chatbots to generate the saved responses. Some answers have had human intervention for clarity or where the A.I. has not been able to answer the question.