Calculate the percentage yield if, on heating 50g of limestone(CaCO3), 21 g of lime(CaO) were obtained.

To calculate the percentage yield, you will need to use the formula:

Percentage Yield = (Actual Yield / Theoretical Yield) x 100

Theoretical yield: The amount of product that should be obtained based on the balanced chemical equation.

Actual yield: The amount of product that is actually obtained.

Let's start by calculating the theoretical yield of lime (CaO) in this reaction.

The balanced equation for the reaction of limestone (CaCO3) to form lime (CaO) is:

CaCO3(s) → CaO(s) + CO2(g)

The molar mass of CaCO3 is 100.09 g/mol, and the molar mass of CaO is 56.08 g/mol.

Step 1: Calculate the moles of CaCO3:
Moles of CaCO3 = Mass of CaCO3 / Molar mass of CaCO3
Moles of CaCO3 = 50 g / 100.09 g/mol
Moles of CaCO3 = 0.4998 mol

Step 2: Calculate the moles of CaO:
Based on the balanced equation, 1 mole of CaCO3 produces 1 mole of CaO.
Therefore, Moles of CaO = Moles of CaCO3 = 0.4998 mol

Step 3: Calculate the theoretical yield of CaO:
Theoretical yield = Moles of CaO x Molar mass of CaO
Theoretical yield = 0.4998 mol x 56.08 g/mol
Theoretical yield = 28.02 g

Now let's calculate the percentage yield using the formula mentioned above:

Percentage Yield = (Actual Yield / Theoretical Yield) x 100
Percentage Yield = (21 g / 28.02 g) x 100
Percentage Yield = 74.93%

Therefore, the percentage yield of lime (CaO) is approximately 74.93%.

To calculate the percentage yield, you need to compare the actual yield (the amount obtained) with the theoretical yield (the amount you would expect to obtain based on stoichiometry and assuming 100% conversion).

Given:
- Mass of limestone (CaCO3) used = 50g
- Mass of lime (CaO) obtained = 21g

First, determine the molar masses of CaCO3 and CaO:

- Molar mass of CaCO3:
Ca: 40.08 g/mol
C: 12.01 g/mol
O: 16.00 g/mol
Total: 40.08 + 12.01 + (3 x 16.00) = 100.09 g/mol

- Molar mass of CaO:
Ca: 40.08 g/mol
O: 16.00 g/mol
Total: 40.08 + 16.00 = 56.08 g/mol

Next, calculate the theoretical yield of CaO based on the stoichiometry of the reaction:

1 mole of CaCO3 produces 1 mole of CaO.
Therefore, the number of moles of CaO produced can be determined using the molar masses:

Number of moles of CaO = Mass of CaO / Molar mass of CaO
= 21g / 56.08 g/mol
≈ 0.3749 mol

Since 1 mole of CaCO3 produces 1 mole of CaO, the theoretical yield of CaO is also 0.3749 mol.

Now, calculate the theoretical mass of CaO:

Theoretical mass of CaO = Number of moles of CaO × Molar mass of CaO
= 0.3749 mol × 56.08 g/mol
≈ 21.03 g

Finally, calculate the percentage yield:

Percentage yield = (Actual yield / Theoretical yield) × 100%
= (21g / 21.03g) × 100%
≈ 99.86%

Therefore, the percentage yield of lime (CaO) is approximately 99.86%.