Yes...another calculation problem.
Rxn:
1ml isopentyl alcohol + 1.5ml glacial acetic acid + 3 drops sulfuric acid=> isopentyl acetate
to calculate the theoretical yield..
I know that the acetic acid is in excess but how would I calculate the theoretical yield?
is it just find moles acetic acid (know excess) and then since I do know that the ratio is 1:1 then I can just find theoretical yield directly?
Another question is...
1) What catalyst is used in the experiment?
I say it's the sulfuric acid.
2) since one method of formation of ester is to add excess acetic acid. What is another way to form the ester which will favor the formation fo ester
I said that you could add excess isopentyl alcohol
3) Why is it easier to remove excess acetic acid from products than excess isopentyl alcohol?
No idea about this question.
Thank you
For Further Reading
Some Lab Question (s) - ~christina~, Saturday, March 8, 2008 at 11:45pm
Is the last question with the "why is it easier to remove excess acetic acid from products than excess isopentyl alcohol?"
because I can just use sodium bicarbonate to remove the acid?
Is there a method to remove the isopentyl alcohol though?
1ml isopentyl alcohol + 1.5ml glacial acetic acid + 3 drops sulfuric acid=> isopentyl acetate
to calculate the theoretical yield..
I know that the acetic acid is in excess but how would I calculate the theoretical yield?
is it just find moles acetic acid (know excess) and then since I do know that the ratio is 1:1 then I can just find theoretical yield directly?
Find theoretical yield by 1 mol isopentyl alcohol gives 1 mol of the ester. If you are not positive that acetic acid is in excess, you can determine theoretical yield (1:1 again) using acetic acid as the starting material. You will then have two theoretical yields for isopentyl acetate; take the smaller one and that will be the limiting reagent. Since both isopentyl alcohol and acetic acid are liquids, you will need density in order to convert mL to grams.
Another question is...
1) What catalyst is used in the experiment?
I say it's the sulfuric acid.
I think that is correct.
2) since one method of formation of ester is to add excess acetic acid. What is another way to form the ester which will favor the formation fo ester
I said that you could add excess isopentyl alcohol
That will work since either reactant in excess will shift the equilibrium to the right and favor the formation of the ester. However, my educated gues is that the prof will consider that the same KIND of shift (adding either one in excess). I suspect the prof may be looking for the removal of isopentyl acetate. How would you do that? By distillation but look up the boiling points of the alcohol, ester, acetic acid, etc to check it out. Several books on synthesis of esters talk about sifting the equilibrium by distilling the ester as it is formed.
3) Why is it easier to remove excess acetic acid from products than excess isopentyl alcohol?
NaHCO3 is the way to go for removal of the two acids. To try to separate two organic compounds, one an alcohol and the other an ester would be MUCH tougher. So we take the easier route.
No idea about this question.
Thank your help Dr.Bob
site
To calculate the theoretical yield of the isopentyl acetate, you are correct that you need to use the ratio between the limiting reagent (isopentyl alcohol) and the product (isopentyl acetate).
First, you need to determine the limiting reagent by comparing the moles of isopentyl alcohol and glacial acetic acid. You mentioned that the acetic acid is in excess, so the limiting reagent is isopentyl alcohol. This means that the number of moles of isopentyl alcohol will determine the maximum amount of product that can be formed.
Next, calculate the number of moles of isopentyl alcohol. To do this, divide the volume of isopentyl alcohol by its molar volume. Since both isopentyl alcohol and isopentyl acetate have a 1:1 mole ratio according to the balanced equation, the moles of isopentyl alcohol will equal the moles of isopentyl acetate.
Finally, you can calculate the theoretical yield in grams by multiplying the number of moles of isopentyl acetate by its molar mass. This will give you the maximum amount of isopentyl acetate that can be formed under ideal conditions.
Regarding the catalyst used in the experiment, you correctly identified sulfuric acid as the catalyst for the reaction. Catalysts are substances that speed up the reaction without being consumed in the process.
To form the ester in favor of the isopentyl acetate, you suggested adding excess isopentyl alcohol. The rationale behind this is that by increasing the concentration of the isopentyl alcohol, you can shift the equilibrium of the reaction towards the desired product.
Concerning the last question about why it is easier to remove excess acetic acid than excess isopentyl alcohol, you mentioned using sodium bicarbonate to neutralize the acid. This is indeed a common method for neutralizing acids. As for removing excess isopentyl alcohol, it can be more challenging because it typically has a higher boiling point and is less volatile than acetic acid. Methods such as distillation or evaporation can be used to remove excess isopentyl alcohol, but they may require higher temperatures and longer processing times compared to removing excess acetic acid.
I hope this helps! Let me know if you have any further questions.