What is the Correct Calculation for Percentage Yield of Alkene from Alcohol?

In summary, we were preparing Alkene from Alcohol & were asked to calculate percentage yield. We used 13.5 ml Cyclohexanol with 13.5 ml water & 7ml Sulfuric acid. To calculate % yield,i need theoretical mass.. So i was calculating no.of moles of cyclohexanol & cyclohexene (the product) to get the theoretical mass. No of moles of cylcohexanol = m/molar massmass = 13.5 ml x 0.926 g/ml (density) = 12.987 gNo.of moles of cyclohexanol = 12.987/100.16 = 0.136 moles
  • #1
ChemDoodle
25
0
We were preparing Alkene from Alcohol & were asked to calculate percentage yield.
We used 13.5 ml Cyclohexanol with 13.5 ml water & 7ml Sulfuric acid.

To calculate % yield,i need theoretical mass..
So i was calculating no.of moles of cyclohexanol & cyclohexene (the product) to get the theoretical mass.

No of moles of cylcohexanol = m/molar mass
mass = 13.5 ml x 0.926 g/ml (density) = 12.987 g
No.of moles of cyclohexanol = 12.987/100.16 = 0.136 moles

No.of moles of cyclohexne = no.of moles of cyclohexanol = 0.136 moles (from stoichiometry)
Theoretical mass of cyclohexene = n x M
=0.136 x 82.14 = 11.17104 g
Is this calculation correct?
 
Last edited:
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  • #2
ChemDoodle said:
We were preparing Alkene from Alcohol & were asked to calculate percentage yield.
We used 13.5 ml Cyclohexanol with 13.5 ml water & 7ml Sulfuric acid.

To calculate % yield,i need theoretical mass..
So i was calculating no.of moles of cyclohexanol & cyclohexene (the product) to get the theoretical mass.

No of moles of cylcohexanol = m/molar mass
mass = 13.5 ml x 0.926 g/ml (density) = 12.987 g
No.of moles of cyclohexanol = 12.987/100.16 = 0.136 moles

Is this calculation correct?

Moreover, i need to calculate no.of moles of cyclohexene..What's the mass of cyclohexene i should take here? Should it be the same as cyclohexanol? Since according to the equation 1mole of cyclohexanol is supposed to yield 1 mole of cyclohexane.

Please help :)


The calculation looks correct. And as you said, next step is to find the number of moles cyclohexene. 1 mole cyclohexanol yield 1 mole cyclohexane, so there are the same numbers of molecules, but you should think about if two molecules have the same molar mass =)
 
  • #3
saxen said:
The calculation looks correct. And as you said, next step is to find the number of moles cyclohexene. 1 mole cyclohexanol yield 1 mole cyclohexane, so there are the same numbers of molecules, but you should think about if two molecules have the same molar mass =)

I edited the first post with the continued calculations.Can u check that for me, please?
 
  • #4
ChemDoodle said:
I edited the first post with the continued calculations.Can u check that for me, please?

It looks ok.
 
  • #5
Thanku very much :D
 
  • #6
ChemDoodle said:
Thanku very much :D

No problem, you know how to calculate the %yield?
 
  • #7
saxen said:
No problem, you know how to calculate the %yield?

Yes :) Actual mass / Theoretical x 100
:D
Thanks for asking,really :) Most helplers here just make me feel inferior lol.
 

What is the definition of percentage yield?

The percentage yield is a measure of the efficiency of a chemical reaction. It represents the percentage of the theoretical yield that is actually obtained in a laboratory or industrial process.

How is percentage yield calculated?

To calculate the percentage yield, you divide the actual yield by the theoretical yield and multiply by 100. The theoretical yield is the maximum amount of product that can be produced based on the amount of limiting reactant, while the actual yield is the amount of product obtained from the reaction in the laboratory.

What factors can affect the percentage yield?

The percentage yield can be affected by a variety of factors such as impurities in reactants, incomplete reactions, side reactions, and experimental errors. It is important to control these factors in order to obtain a high percentage yield.

Why is it important to calculate percentage yield?

Calculating the percentage yield is important for several reasons. It allows scientists to evaluate the efficiency of a reaction and identify any sources of error. It also helps in determining the amount of reactants needed for a reaction to produce a desired amount of product, which is crucial in industrial processes.

What is a good percentage yield?

A good percentage yield is typically considered to be above 90%. However, the expected percentage yield can vary depending on the reaction and the conditions under which it is carried out. A yield of 100% is rarely achieved due to factors such as impurities and losses during the purification process.

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