Question

 Experiment 6: The Standardization of a Basic Solution and the Determination of the MM of an Acid

 *Note: This experiment is relatively long unless you know precisely what to do. Read the experiment before coming to class and arrive on time.

 After reading through the experiment answer the following question:

 1. 7.0 mL of 6.0 M NaOH are diluted with water to a volume of 400 mL. You are asked to find the molarity of the resulting solution.

 a. First find out how many moles of NaOH there are in 7.0 mL of 6.0 M NaOH. 

 b. Since the total number of moles of NaOH is not changed on dilution, the molarity after dilution can be found by dividing by the final volume of the solution. Calculate that molarity.

 2. In an acid-base titration, 23.91 mL of an NaOH solution are needed to neutralize 24.58 mL of a 0.1002 M HCI solution. To find the molarity of the NaOH solution, we can use the following procedure:

 a. First note the value of MH- in the HCI solution (given).

 b. Find in the MoH- of NaOH in the solution.

 c. Obtain MNaoн from Moн.

 A 0.3174 g sample of an unknown acid requires 26.23 mL of 0.1056 M NaOH for neutralization to a phenolphthalein end point. There are 0.27 mL of 0.1096 M HCI used for back-titration.

 a. How many moles of OH^-  are used? How many moles of H⁺  from HCI?

 b. How many moles of H⁺ are there in the solid acid?

 c. What is the molar mass of the unknown acid?

Answer 1