Solubility Products, Common Ion Effect, Hardness of Water : Experimental Procoline

            Procedures in experiment are interesting for scientist, student, or/ and researchers, chemist. Must be properly guide and be always have safely tools on it. There are 2 procedure on this experiment these are Determination of  K_sp  and Molar Solubility of Ca(OH)₂

and Molar Solubility of Ca(OH)₂ in the presence of Ca⁺² .

Part I. Determination of  K_sp  and Molar Solubility of Ca(OH)₂

1.      Prepare two 50-mL burets then clamp it. Fill each by a tap water and 1.25 x 10^-3 Rinse the clean buret and on tap water dispense 25.00ml of water into a 125mL Erlenmeyer flask tip with two 2-mL portions of standardized NH₃-NH₄Cl solution Erlenmeyer flask.

2.      Next add 4 drops of eriochromeblack T indicator to the Erlenmeyer flash, Swirl, then place the Erlenmeyer flask under the burret containing the EDTA (red wine color). When it turns blue its good indication and the processed is done.

3.      Take a filter paper, fold it in quarters and partially in cone like a funnel and place it into 250 ml beaker. Slowly filter it on said experiment.

Rinse a 50-mL pipet with 1 or 2 mL of the saturated Ca(OH)₂ solution and discard.  Pipet 50.00 mL of the filtrate into a clean 125-mL Erlenmeyer flask and add 4 drops of eriochromeblack T  indicator. Record the EDTA burret. Titrate with the standard HCl solution. Record the finaL volume (± 0.01mL) needed to just turn the solution color from red wine color to blue. Repeat the titration with two new samples of Ca(OH)₂.

Part II. Determination of  Molar Solubility of Ca(OH)₂ in the presence of Ca⁺²

1.      Repeat Part I, steps 2 – 3.

2.      Add 2ml of buffer solution to the Erlenmeyer flask followed by 4 drops eriochromeblack T indicator. Place this flask to burret with EDTA and record the titrate result done for the solution turn to blue.

Data

Part A

Name of salt being used is:                 Calcium sulfate

Formula of the salt being used is:        CaSO₄

Mass of salt used is:                             0.5g

Volume of water used:                         125mL

Part 

Name of the same salt used as used in Part A is                    Calcium sulfate             

Formula of the same salt used as used in Part A is                 CaSO₄            

Mass of salt used is:                                                                 0.5g

Identity of the common ion salt (Na₂SO₄ or NaF)                 Na₂SO₄                       

Concentration of the stock solution                                       0.01

Volume of the stock solution used                                         100 mL

Part C

	Trial 1	Trial 2	Trial 3
Initial tap water buret reading/mL	0	0	0
Final tap water buret reading/mL	25	25	25
Volume of the tap water dispensed from the buret/mL	25	25	25
Initial EDTA buret reading/mL	0	0	0
Final EDTA buret reading/mL	40	40	40
Volume of EDTA used for the titration/mL	40	40	40

Part D

Initial volume reading of buret containing the filtered salt solution 4.5 mL

Final Volume reading of buret containing th filtered salt solution 4.7 mL

V_casoln = volume of the filtered salt solution used (32)-(31) is 0.2 mL

Initial volume reading of EDTA buret is 25 mL

Final volume reading of EDTA buret is 46 mL

V_EDTA = Volume of EDTA used in (35)-(34) 25 mL

Part E

Initial volume reading of buret containing the filtered salt/common ion solution 40 mL

Final volume reading of buret containing the filtered salt/common ion solution 43 mL

V_casoln =  Volume of filtered salt/common solution used = (41) – (40) = 3 mL

Initial volume reading of EDTA buret is 20 mL

Final volume reading of EDTA buret is 49 mL

V_EDTA = Volume of EDTA used in (44)-(43) 29 mL