) Experiment 7-Pre-LabS University of Kentucky x C Chegg Study | Guided Sc x d w

Question

) Experiment 7-Pre-LabS University of Kentucky x C Chegg Study | Guided Sc x d www.saplinglearning.com/ibiscms/mod/ibis/view.php?id=4057476 Sapling Learning macmilan learming Destiny Young Jump to... Attempts Score Print Calculator-' Periodic Table Question 8 of 9 Available From 10/23/2017 07:00 AM Due Date Late submissions: Allowed with 25% of the Map 10/30/2017 05:00 PM Sapling Learning points possible deducted per day until 10/31/2017 05:00 PM mL The flask shown here contains 0.381 g of acid and a few drops lein indicator in water. The buret contains 0.180 M NaOH 10 Points Possible: 10 What volume of base is needed to reach the end point of the titration? 20 Grade Category: Graded Number mL base Policies: 45 You can check your answers. You can view solutions when you complete or give up on any question. You can keep trying to answer each question until you get it right or give up. You lose 5% of th Click to begin What is the molar mass of the acid (assuming it is diprotic and that the end point corresponds to the second equivalence pcint)? Add base to the solution untw it just turns pink. You may need to reset the titration if you go past the end point Number e points available to each for each incorrect r in your question attempt at that answer eTextbook Help With This Topic Previous Give Up & View Solution > Check Answer Next Exit Hint Microsoft Edge 11:46 AM O Type here to search 10/30/2017

Explanation / Answer

According to the question;

As we know that;

26 mL is needed to reach the equivalence point.

Now, in order to calculate the molar mass, ans we already know that the acid is diprotic we do the following

2OH- + H2A ---b--> A2- + H2O

Then,

moles OH/moles H2A= 2/1
moles OH-/2 = moles H2A

Then,

moles H2A = 0.180 * 0.026 / 2

moles H2A = 0.00234 moles

Then,

MW= 0.0381 g / 0.00234 mol

MW = 162.82 g/mol

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