When 50.0g of silicon dioxide is heated with an excess of carbon 32.2 g of silicon carbide I'd produced.
SiO2(s) + 3C(s) → SiC(s) + 2CO(g)
A. What is the percent yield of this reaction?
B. How many grams of CO gas are made?
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To find the percent yield of the reaction, you need to compare the actual yield (32.2 g of silicon carbide, SiC) to the theoretical yield (the maximum amount of SiC that could be produced based on the given amount of silicon dioxide, SiO2).
Step 1: Calculate the theoretical yield of SiC.
First, determine the molar masses of SiO2 and SiC:
- Molar mass of SiO2 = 28.09 g/mol (atomic mass of Si: 28.09 g/mol + atomic mass of O: 16.00 g/mol)
- Molar mass of SiC = 40.10 g/mol (atomic mass of Si: 28.09 g/mol + atomic mass of C: 12.01 g/mol)
Since the balanced chemical equation states that 1 mole of SiO2 produces 1 mole of SiC, you can directly compare the molar masses:
- Ratio of molar masses: Molar mass of SiO2 / Molar mass of SiC = 28.09 g/mol / 40.10 g/mol ≈ 0.700
- Theoretical yield of SiC = 0.700 * 50.0 g (mass of SiO2) ≈ 35.0 g
Step 2: Calculate the percent yield.
The percent yield is given by the formula:
Percent Yield = (Actual Yield / Theoretical Yield) * 100
In this case:
- Actual yield = 32.2 g
- Theoretical yield = 35.0 g
Percent Yield = (32.2 g / 35.0 g) * 100 ≈ 92.0%
Therefore, the percent yield of the reaction is approximately 92.0%.
To determine how many grams of CO gas are produced, you need to refer to the balanced chemical equation. From the equation:
SiO2(s) + 3C(s) → SiC(s) + 2CO(g)
It is stated that 1 mole of SiC produces 2 moles of CO. Thus, the ratio of moles of CO to SiC in the reaction is 2:1.
Step 1: Convert the given mass of SiC into moles.
Moles of SiC = Mass of SiC / Molar mass of SiC = 32.2 g / 40.10 g/mol ≈ 0.804 mol
Step 2: Determine the number of moles of CO produced.
Since the ratio of CO to SiC is 2:1, the number of moles of CO produced is twice the moles of SiC:
Moles of CO = 2 * 0.804 mol = 1.608 mol
Step 3: Convert moles of CO to grams.
Mass of CO = Moles of CO * Molar mass of CO = 1.608 mol * 28.01 g/mol ≈ 45.1 g
Hence, approximately 45.1 grams of CO gas are produced in the reaction.
Convert 50 g SiO2 to mols. mols = grams/molar mass.
Using the coefficients in the balance chemical equation convert moles SiO2 to SiC.
Convert moles SiC to grams. g = mols x molar mass. This is the theoretical yield.
Percent yield = (actual yield/theoretical yield)*100 = ?
Part B is in the same way as part A. Post your work if you get stuck.