Reaction: C6H11OH(l) ==> C6H10(l) + H2O(l)
Calculate the mass of cyclohexanol (C6H11OH) needed to produce 45.0g cyclohexene (C6H10) by reaction if the reaction has a 86.2% yield and the cyclohexanol is 92.3% pure.
Usually this problem would be fairly easy, but the purity is throwing me off. How does the purity relate to this question?
When heated with sulfuric or phosphoric acid, cyclohexanol, C6H11OH is converted to cyclohexene, C6H10. The balanced chemical equation for the reaction is shown below. C6H11OH(l) → C6H10 (l) + H2O(l) If the percent yield is 83%, what mass of cyclohexanol must we use to obtain 25 g of cyclohexene?
After you finish the calculation to find the g cyclohexanol needed with 86.2% yield, that is if the cyclohexanolis 100% pure. Since it is only 92.3% pure, the amount for 100%/0.923 = amount needed for 92.3% purity.
Thank you so much!
You don't need to memorize a new formula for this. Remember what you do for %yield. It is
%yield = (actual amount/theoretical yield)*100
92.3 = actual amount/theoretical yield
theoretical = actual/%yield
In this question, the purity of cyclohexanol relates to the amount of actual cyclohexanol present in a given sample. When a substance is not 100% pure, it means there are impurities present that are not the desired compound. In this case, the cyclohexanol is 92.3% pure, which means that only 92.3% of the sample is actually cyclohexanol, and the remaining 7.7% is impurities.
To calculate the mass of cyclohexanol needed to produce a given amount of cyclohexene, we need to take into account both the reaction yield and the purity of the cyclohexanol.
First, let's determine the theoretical mass of cyclohexanol needed to produce 45.0g of cyclohexene based on the balanced chemical equation:
C6H11OH(l) ==> C6H10(l) + H2O(l)
The molar ratio between cyclohexanol and cyclohexene is 1:1. This means that for every mole of cyclohexanol reacted, we will produce 1 mole of cyclohexene.
Next, we need to convert the given amount of cyclohexene (45.0g) to moles. To do this, we divide the mass of cyclohexene by its molar mass:
Molar mass of cyclohexene (C6H10) = (6 x atomic mass of carbon) + (10 x atomic mass of hydrogen) = 6(12.01) + 10(1.01) = 82.16 g/mol
Moles of cyclohexene = Mass of cyclohexene / Molar mass of cyclohexene = 45.0g / 82.16 g/mol
Now, since the reaction has a yield of 86.2%, we multiply the calculated moles of cyclohexene by the yield to determine the actual moles of cyclohexene produced:
Actual moles of cyclohexene = Moles of cyclohexene x Yield = (45.0g / 82.16 g/mol) x 0.862
Finally, to determine the mass of cyclohexanol needed, we need to find the moles of cyclohexanol. Since the molar ratio between cyclohexanol and cyclohexene is 1:1, the moles of cyclohexanol needed will be equal to the moles of cyclohexene:
Moles of cyclohexanol needed = Actual moles of cyclohexene
Now that we have the moles of cyclohexanol needed, we can calculate the mass by multiplying by the molar mass of cyclohexanol:
Molar mass of cyclohexanol (C6H11OH) = (6 x atomic mass of carbon) + (11 x atomic mass of hydrogen) + (1 x atomic mass of oxygen) = 6(12.01) + 11(1.01) + 1(16.00) = 100.16 g/mol
Mass of cyclohexanol needed = Moles of cyclohexanol x Molar mass of cyclohexanol
By using these steps and considering the purity of the cyclohexanol, you will be able to calculate the mass of cyclohexanol needed to produce a specified amount of cyclohexene.