What is the percentage yield of the reaction of 4.9 g isoamyl alcohol with 4.9 g of acetic acid if 3.5 g of isoamyl acetate product is obtained after distillation?
Enter your answer, without a % symbol, to 2 sig. figs.
This is a limiting reagent (LR) problem. You know that when amounts have been given for BOTH reactants.
I'll use abbreviations
alco + acetic ==> acetate + H2O
mols alco = grams/molar mass
mols acetic = grams/molar mass
Using the coefficients in the balanced equation, convert mols alco to mols acetate.
Do the same for mols acetic to mols acetate.
It is likely that these two values will not agree; the correct answer in LR problems is ALWAYS the smaller value.
Convert the smaller value to grams. grams = mols acetate x molar mass of the isoamyl acetate. This is the theoretical yield (TY).
The actual yield (AY) is given in the problem as 3.5g.
%yield = (AY/TY)*100 = ?
71.42%
To calculate the percentage yield, you can use the formula:
Percentage Yield = (Actual Yield / Theoretical Yield) * 100
In this case, the actual yield is given as 3.5 g of isoamyl acetate product.
To determine the theoretical yield, you need to find the limiting reactant. The limiting reactant is the one that is completely consumed and determines the maximum amount of product that can be formed. To do this, you can compare the moles of reactants.
1. First, convert the given masses of reactants to moles.
- Moles of isoamyl alcohol = 4.9 g / molar mass of isoamyl alcohol
- Moles of acetic acid = 4.9 g / molar mass of acetic acid
2. Next, calculate the moles of product that can be formed from each reactant, assuming they react in a 1:1 mole ratio.
- Moles of isoamyl acetate from isoamyl alcohol = moles of isoamyl alcohol
- Moles of isoamyl acetate from acetic acid = moles of acetic acid
3. Compare the moles of product from each reactant. The smaller value represents the limiting reactant.
4. Once you have identified the limiting reactant, calculate the theoretical yield of the product in grams.
- Theoretical Yield = moles of limiting reactant * molar mass of isoamyl acetate
5. Finally, plug the values of the actual and theoretical yield into the percentage yield formula to find the percentage yield.
Follow these steps to find the answer to the question.