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macmillan learning mL Reset e flask shown here contains 0.633 g of acid and a fe

ID: 555260 • Letter: M

Question

macmillan learning mL Reset e flask shown here contains 0.633 g of acid and a few drops or phenolphthalein indicator dissolved in water. The buret contains 0.140 M NaOH 5 15 20 25 30 35 40 45 50 20 25 30 What volume of base is needed to reach the end point of the titration? Number mL base What is the molar mass of the acid (assuming it is diprotic and that the end point corresponds to the second equivalence point)? Add base to the solution until it just turns pink. You may need to reset the titration if you go past the end point Number g/ mol Previous Give Up & View Solution O Check Answer Next Exit Hint

Explanation / Answer

volume of base consumed = 24 ml

no of mol of base reacted = 0.14*24 = 3.36 mmol

no of mol of acid reacted = 3.36 mmol = 0.00336 mol

molarmass of acid = w/n = 0.633/0.00336 = 188.4 g/mol