A student measures out exactly 0.105 g of salicylic acid and runs the experiment as dictated in the lab manual. They obtain 0.111 g of aspirin. What is the percent yield for their reaction?

The percent yield of the reaction is 8.10 %.

Explanation:

To calculate the number of moles, we use the equation:

     .....(1)

Given mass of salicylic acid = 0.105g

Molar mass of salicylic acid = 138.12 g/mol

Putting values in equation 1, we get:

The chemical equation for the formation of aspirin from salicylic acid follows:

By Stoichiometry of the reaction:

1 mole of salicylic acid produces 1 mole of aspirin

So, 0.0076 moles of salicylic acid will produce = of aspirin

Now, calculating the mass of aspirin from equation 1, we get:

Molar mass of aspirin = 180.16 g/mol

Moles of aspirin = 0.0076 moles

Putting values in equation 1, we get:

To calculate the percentage yield of aspirin, we use the equation:

Experimental yield of aspirin = 0.111 g

Theoretical yield of aspirin = 1.37 g

Putting values in above equation, we get:

Hence, the percent yield of the reaction is 8.10 %.

the ozone layer acts as a filter for the shorter wavelength and highly hazardous ultraviolet radiation (uvr) from the sun, protecting life on earth from its potentially harmful effects. when the sky is clear, there is an inverse relationship between stratospheric ozone and solar uvr measured at the earth's surface.

answer : a model is often used to explain and make things easier to understand when any scientific topic needs to be demonstrated and explained.

as in this case where a scientist wants to use a model to present the results of his detailed scientific investigation. he should do it as it will him to make the audience understand the concept in a much better way. also, it can be changed according to new scientific understandings.