What is the theoretical yield of ethyl chloride in the reaction of 20.2 g of ethylene with 53 g of hydrogen chloride? (For ethylene, 28 amu; for hydrogen chloride,36.5amu ; for ethyl chloride, 64.5 amu.) What is the percent yield if 23.5g of ethyl chloride is actually formed?
This is a limiting reagent problem. How do I know that? Because amounts for BOTH reactants are given.
Write the equation and balance it.
2a. Convert 20.2 g ethylene to mols. mols = grams/molar mass.
2b. Do the same for HCl.
3a. Using the coefficient in the balanced equation, convert mols ethylene from 2a to mols ethyl chloride.
3b. Do the same for HCl
3c. You will obtain different answers for mols ethyl chloride; of course, one of those must be wrong. The correct answer in limiting reagent problems is ALWAYS the smaller one and the reactant producing that value is the limiting reagent.
4. Using the smaller number to convert to grams. g = mols x molar mass. This is the theoretical yield.
5. %yield = (actual yield/theoretical yield)(100 = ??
To find the theoretical yield of ethyl chloride, we need to determine the limiting reactant in the reaction. This can be done by calculating the amount of ethyl chloride that can be produced from each reactant and comparing them.
Step 1: Convert the masses of ethylene and hydrogen chloride to moles.
Molar mass of ethylene (C2H4) = 2*12.01 + 4*1.01 = 28.05 g/mol
Molar mass of hydrogen chloride (HCl) = 1.01 + 35.45 = 36.46 g/mol
Moles of ethylene = mass / molar mass = 20.2 g / 28.05 g/mol ≈ 0.72 mol
Moles of hydrogen chloride = mass / molar mass = 53 g / 36.46 g/mol ≈ 1.45 mol
Step 2: Write the balanced chemical equation for the reaction.
C2H4 + HCl → C2H5Cl
Step 3: Use the stoichiometry of the reaction to determine the moles of reactants required to produce ethyl chloride.
From the balanced chemical equation, we can see that 1 mole of ethylene reacts with 1 mole of hydrogen chloride to produce 1 mole of ethyl chloride. Therefore, the ratio of moles is 1:1:1.
Step 4: Determine the limiting reactant.
Based on the mole ratio, we can see that ethylene and hydrogen chloride are present in a 1:1 ratio. Since we have more moles of hydrogen chloride (1.45 mol) than ethylene (0.72 mol), the ethylene is the limiting reactant.
Step 5: Calculate the theoretical yield of ethyl chloride.
Since ethylene is the limiting reactant, the amount of ethyl chloride formed will be based on the moles of ethylene.
Molar mass of ethyl chloride (C2H5Cl) = 2*12.01 + 5*1.01 + 35.45 = 64.53 g/mol
Theoretical yield of ethyl chloride = moles of ethylene * molar mass of ethyl chloride
= 0.72 mol * 64.53 g/mol
≈ 46.48 g
Therefore, the theoretical yield of ethyl chloride is approximately 46.48 g.
To calculate the percent yield, we need the actual yield of ethyl chloride.
Given: Actual yield = 23.5 g
Step 6: Calculate the percent yield.
Percent yield = (actual yield / theoretical yield) * 100
= (23.5 g / 46.48 g) * 100
≈ 50.6%
Therefore, the percent yield of ethyl chloride is approximately 50.6%.
To calculate the theoretical yield of ethyl chloride, we need to determine the limiting reactant, which is the reactant that is completely consumed in the reaction and thus determines the maximum amount of product that can be formed.
First, we need to calculate the moles of each reactant by dividing the given mass by their respective molar masses:
Moles of ethylene (C2H4) = mass / molar mass = 20.2 g / 28 g/mol = 0.721 mol
Moles of hydrogen chloride (HCl) = mass / molar mass = 53 g / 36.5 g/mol = 1.452 mol
Next, we need to determine the mole ratio between the reactants according to the balanced chemical equation. The balanced equation for the reaction is:
C2H4 + HCl -> C2H5Cl
From the balanced equation, we see that 1 mole of ethylene reacts with 1 mole of hydrogen chloride to produce 1 mole of ethyl chloride.
Since the mole ratio is 1:1, the limiting reactant is determined by the reactant with the smaller number of moles, which in this case is ethylene (0.721 mol). Therefore, ethylene is the limiting reactant in this reaction.
To calculate the theoretical yield, we multiply the moles of the limiting reactant by the molar mass of ethyl chloride:
Theoretical yield = Moles of limiting reactant * molar mass of ethyl chloride
Theoretical yield = 0.721 mol * 64.5 g/mol = 46.5245 g
Therefore, the theoretical yield of ethyl chloride is 46.5245 grams.
To calculate the percent yield, we need to compare the actual yield (23.5 g) to the theoretical yield (46.5245 g) and express it as a percentage:
Percent yield = (Actual yield / Theoretical yield) * 100
Percent yield = (23.5 g / 46.5245 g) * 100 = 50.6%
Therefore, the percent yield of ethyl chloride is 50.6%.