ily has a mixture of 4 compounds that they want to separate. All 4 compounds appear as white solid powders. When Lily adds 25 mL of chloroform (density = 1.492 g/mL; bp = 61C) to the mixture, everything dissolves with stirring. Lily decides to use acid-base extraction to separate the compounds from one another. Chloroform and water are immiscible, and all acids and bases will be prepared in water.  1. First, Lily tries extracting the organic solution with 1.0 M HCl (20 mL). Which layer will be the organic layer in the separatory funnel? - top layer -bottom layer - only one layer   2. What will be in the organic layer after the extraction with 1.0 M HCl? - 1,3,4 -2 only -1,2,3,4 -nothing will be left in organic layer   3. Lily sets the first aqueous layer aside and returns the organic layer to the separatory funnel. Next, they choose to extract with 0.50 M NaOH (20 mL). What will be left in the organic layer after this step? -1,3,4 -2,3 -1,3,4 as salts -2 only   4. What should the pH of the water be after Lily combines the two aqueous layers? - greater than 7 -7 -less than 7   5. Calculate the pH of the aqueous combined aqueous layers. Remember that pH = - log[H+] where the concentration is in M. 6. After combining the two aqueous layers and adjusting the pH to 2, Lily observes solid precipitate out of solution. They cool it in an ice bath and then collect the solid by vacuum filtration. What is this solid? - 1,4 as salts - 1,3,4 as salts -1,4 -1,3,4   7. Lily realizes that the solid they have collected is not a pure compound but a mixture. They re-dissolve it in 25 mL of chloroform and try extracting with 5% NaHCO3 (20 mL) instead. What will be in the aqueous layer after this step? -3,4 as salts -1,3,4 as salts -3 as a salt -1,4 as salts   8. Will anything be left from the organic layer after Lily dries it and evaporates off the solvent?   - nothing will be left -3 -3 as a salt -2   9. How could 1 and 4 be separated from each other? (IMAGE INCLUDED) - Re-dissolve in chloroform and extract with HCl - Re-dissolve in chloroform and extract with NaHCO3 - They cannot be separated from each other with acid-base extraction - Re-dissolve in chloroform and extract with NaOH

it is time for the titration.  You measure 15.0 mL of the H2C2O4 solution with a 100-mL graduated cylinder and add it to a 125-mL Erlenmeyer flask.  Then you add two drops of the indicator, phenolphthalein, to the oxalic acid solution in the flask.  You dispense the NaOH solution from the buret into the flask (while swirling the flask) until you reach the endpoint.  At the endpoint, the solution in the flask turns light pink.  You repeat the titration two additional times for a total of three trials.  H2C2O4 (aq) + 2 NaOH (aq) --> Na2C2O4 (aq) + 2 H2O (l)                                                (I)              (II)                (III) Volume of H2C2O4 used  15.00 mL   15.00 mL   15.00 mL Initial Buret Reading        0.00 mL    0.05 mL         0.10 mL Final Buret Reading           14.45 mL     14.38 mL    15.40 mL Volume NaOH used           ________mL          ________mL        ______mL Moles NaOH                     _______M      ________M    _________M…

A chemistry student weighs out 0.159 g of ascorbic acid (H,C,H,0), a diprotic acid, into a 250. mL volumetric flask and dilutes to the mark with distilled water. He plans to titrate the acid with 0.0800M NaOH solution. Calculate the volume of NaOH solution the student will need to add to reach the final equivalence point. Be sure your answer has the correct number of significant digits. mL

What do you understand about the manufacture of chemical solutions? How to (a) make 1000 mL of 0.2 N hydrochloric acid solution from 1 N standard solution and (b) make 100 mL of 0.5 N sodium hydroxide secondary standard solution (known BM = 40 g / mL)? Explain!