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While you are doing the above titration your partner is doing titration 2, to de

ID: 878727 • Letter: W

Question

While you are doing the above titration your partner is doing titration 2, to determine MSA. They weigh out 208.5 mg of pure saliclyic acid (SA) on the analytical balance. After dissolving the mass in ethanol and water, they titrate the solution to the phenolphtalein equivalence point. By subtracting the initial buret reading from the final one, they find that the amount of KOH consumed Is equal to 25.16 mL. What value of MSA (mg / mmol ) did your partner give to you? Enter a numeric answer only, in the correct number of significant figures. Do not enter units.

Explanation / Answer

Note : (There is no clarity in the question.The complete experiment could have been given)

Salicylic acid is C6H4(OH)(COOH)= C7H6O3

Molecular mass of Salicylic acid = 7x12 + 6x1 + 3x16 = 138

1 Mole of Salicylic acid = 138 g (Molecular mass expressed in gram)

138 g of Salicylic acid = 1 mole

208.5 mg of Salicylic acid = 0.2085 g of Salicylic acid = 0.2085 g / 138 g   mole = 0.0015 mol = 1.5 x 10-3 mol

                                                                                                                                                 = 1.5 mmol

Without unit MSA = 1.5