Question

Tast lab Experiment #7 The Solubility Product -Constant (Ksp) Objectives To calculate the Kop values of some salts II. Background: Research and provide definition/principles for -K and how to obtain its value III Procedure dish for before performingthe actual procedure, prepare a perfectly tarred evaporating consistent "dry" mass by heating it, cooling and weighing. cat again, cool and weigh until the difference in masses is or <0.0010. wote: Use the same analytical balance and DO NOT touch the dish with bare hands- 1) (Preparing a saturated solution) I-a. In a large test tube, mix a few grains of the first salt with 20 mL of water and stir or agitate. 1-5 Continue adding the salt a few grains at a time with stirring or agitation) until the added salt no longer dissolves. Let the solution stand for a few minutes Withdraw 5 mL of the supernatant liquid using a pipette and place this volume in a pre-weighed clean and very dry evaporating dish. Cover with a watch glass and evaporate gently using an air bath over a Bunsen Burner or a hot plate on high setting. Cool and re-weigh the evaporating dish to obtain the mass of salt in the 5 ml saturated solution. Determine the concentration of the salt used in the saturated solution. Calculate the Ksp. 5) Repeat Procedures 1 - 6 using a second salt. 1,47 x 10 moles 0.022 IV Suggested format for Data and Results Tabulated) - Kielor Mass of Salt Molar Solubility or Salt Avg. Mass of Evap, Dish (empty Mass of Salt + Evaporating Dish Casou 84.02 Bason 81.63 8405a 0.02 81.64g 10.01 7.35003 12,14810 31 Chem, 1412, Experiment #1, Page 25 of 33

Answer 1

Ksp (CaSO4) = [Ca2+][SO42-]

= S×S = 7.35×10^-3×7.35×10^-3

= 5.40×10^-5

Ksp (BaSO4) = [Ba2+][SO42-]

=S×S = 2.14×10^-3×2.14×10^-3

= 4.58×10^-6