A saturated solution is prepared by adding excess PbI2 (s) to distilled water to form 1.0L of solution at

25°C. The concentration of Pb
2+
(aq) in the same saturated solution is found to be 1.3 x 10
-3 M. The

chemical equation for the dissolution of PbI2

(s) in water is shown below.

PbI2
(s) ⇄ Pb
2+
(aq) + 2 I
-
(aq)

a. Write the equilibrium-constant expression for the equation
b. Calculate the molar concentration of I
-
(aq) in the solution
c. Calculate the value of the equilibrium constant, Ksp
d. An additional 1.0 L of water is added, bringing the total volume of the solution to 2.0 L and the
solution remains saturated. Calculate the molar concentration of Pb
2+
(aq) in the solution.

e. Solid NaI is added to the saturated solution of PbI2

. Assuming the volume of the solution does

not change, does the molar concentration of Pb
2+
(aq) in the solution increase, decrease, or

remain the same? Justify your answer.

Salicylic acid is a very important acid. it is used to synthesize the aspirin by treating with acetic anhydride. a 0.2015-g sample of salicylic acid was dissolved in a 100.00-ml volumetric flask, and the solution was diluted to the mark. a 10-ml aliquot of this solution was titrated with standard naoh (0.01130 + 0.2% n) to a phenolphthalein faint pink color end point at 19.81 ml. (a) (calculate the normality of the salicylic acid solution used in the titration. (b) assuming the salicylic acid is pure, what is the equivalent weight of the salicylic acid? practice problems for the final exam (continued) (c) (calculate the inherent error in the determination of the equivalent weight you calculated in part (b). use the following absolute errors in the equipment /glassware when calculating the inherent error. 5.00-ml pipet: + 0.02 ml 100-ml volumetric flask: + 0.08 ml analytical balance: + 0.2 mg 25-ml buret: + 0.03 ml

Which formula can be used to calculate the molar mass of hydrogen peroxide

The valence of aluminum is +3, and the valence of the chlorine is -1. the formula fir the aluminum chloride is correctly written as