Question

Consider the reaction of cyclohexanol and an acid catalyst to obtain cyclohexene.

Cyclohexanol (100.16 g/mol) --> Cyclohexene (82.14 g/mol)

A reaction was performed in which 3.1 g of cyclohexanol was reacted with an acid catalyst to obtain 2.2 g of cyclohexene. Calculate the percent yield for this reaction (in %).

Answer 1

Answer : The percent yield of the reaction is, 86.5 %

Solution : Given,

Mass of Cyclohexanol = 3.1 g

Molar mass of Cyclohexanol = 100.16 g/mole

Molar mass of Cyclohexene = 82.14 g/mole

First we have to calculate the moles of Cyclohexanol.

`\text{ Moles of Cyclohexanol }=\frac{\text{ Mass of Cyclohexanol }}{\text{ Molar mass of Cyclohexanol }}=(3.1g)/(100.16g/mole)=0.03095moles`

Now we have to calculate the moles of Cyclohexene.

The balanced chemical reaction is,

`Cyclohexanol\rightarrow Cyclohexene`

From the reaction, we conclude that

As, 1 mole of Cyclohexanol react to give 1 mole of Cyclohexene

So, 0.03095 mole of Cyclohexanol react to give 0.03095 mole of Cyclohexene

Now we have to calculate the mass of Cyclohexene.

`\text{ Mass of Cyclohexene}=\text{ Moles of Cyclohexene}* \text{ Molar mass of Cyclohexene}`

`\text{ Mass of Cyclohexene}=(0.03095moles)* (82.14g/mole)=2.542g`

Theoretical yield of Cyclohexene = 2.542 g

Experimental yield of Cyclohexene = 2.2 g

Now we have to calculate the percent yield of reaction.

`\% \text{ yield of reaction}=\frac{\text{ Experimental yield of Cyclohexene}}{\text{ Theretical yield of Cyclohexene}}* 100`

`\% \text{ yield of reaction}=(2.2g)/(2.542g)* 100=86.5\%`

Therefore, the percent yield of the reaction is, 86.5 %