Question

Starting with 7.2 g of salicylic acid, how many grams of acetylsalicylic acid (theoretical yield) can be made? Assume salicylic acid is the limiting reagent and a one to one stoichiometry. Use the molecular weights that you have already calculated. Give two significant digits.

Answer 1

Ans. Given, 1 mol Salicylic acid forms 1 mol Acetylsalicylic acid   ----- statement 1

1 Salicylic acid + A --------> 1 Acetylsalicylic acid

Number of moles of salicylic acid = mass of salicylic acid / molecular mass of salicylic acid

                                                = 7.2 g/ 138.21 g mol^-1

                                                = 0.0521 mol

So, the number of moles of salicylic acid = 0.0521 mol

Also, the number of moles of Acetylsalicylic acid produced = 0.0521 mol             [see: statement 1]

Now,

Mass of acetylsalicylic acid produced = (moles x molecular mass) of acetylsalicylic acid

                                                = 0.0521 mol x 180.157 g mol^-1

                                                = 9.39 g

Therefore, amount of acetylsalicylic acid produced from 7.2 g salicylic acid = 9.39 g