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Map dom Sapling Learning macmillan learning mL Reset The flask shown here contai

ID: 1017471 • Letter: M

Question

Map dom Sapling Learning macmillan learning mL Reset The flask shown here contains 0.160 g of acid and a few drops of phenolphthalein indicator dissolved in water. The buret contains 0.110 M NaOH 5 15 20 25 30 35 40 45 What volume of base is needed to reach the end point of the titration? Number 15 mL base Assuming the acid is monoprotic, what is its molar mass? 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 Tools 102

Explanation / Answer

volume of base from the buret reading = 10.1 mL

moles of base = molarity x volume / 1000

                       = 0.110 x 10.1 / 1000

                        = 1.111 x 10^-3

moles of base = moles of acid

moles of acid = 1.111 x 10^3

moles = mass / molar mass

1.111 x 10^-3 = 0.160 /molar mass

molar mass = 144 g/mol