Question

One step in making para-aminobenzoic acid, PABA, an ingredient in some suntan lotions,

involves replacing one of the hydrogen atoms in a toluene molecule with an - NO2 group,
directly opposite the -CH3 group. Calculate the percent yield if 550 g of toluene added to an
excess of nitric acid provides 305 g of the nitrotoluene product.​

Answer 1

The percentage yield of the reaction is 37.24%.

Step-by-step explanation:

Experimental yield of nitrotoluene product = 305 g

Theoretical yield of nitrotoluene product = ?

Percentage yield:

`\% yield =\frac{\text{Experimental yield}}{\text{Theoretical yield}}* 100`

Theoretical yield of nitrotoluene product:

`CH_3-C_6H_5+HNO_3\rightarrow CH_3-C_6H_4-NO_2+H_2O`

Moles of toluene =
`(550 g)/(92 g/mol)=5.9783 mol`

According to reaction 1 mole of toluene gives 1 mole of nitrotoluene product.

Then 5.9783 moles of toluene will give:

`(1)/(1)* 5.9783 mol=5.9783 mol` of nitrotoluene.

Mass of 5.9783 moles of nitrotoluene:

5.9783 mol × 137 g/mol = 819.03 g

Percentage yield of the reaction:

`\% yield =\frac{\text{Experimental yield}}{\text{Theoretical yield}}* 100`

`\% yield =(305 g)/(819.03 g)* 100=37.24\%`