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answer all 1 Consider the reaction a. Calculate K for the reaction b will Ba504

ID: 1046728 • Letter: A

Question

answer all

1 Consider the reaction a. Calculate K for the reaction b will Ba504 precipitate if Na,So, is added to a saturated solution of Baf,? Explain. Pick either #2 or #3 and answer the question. Please show all work. Before lead in paint was discontinued, lead chromate was a common pigment in yellow paint. A 1.0L solution is prepared by mixing o 50 mg of lead nitrate with 0.020 mg of potassium chromate a. Will a precipitate form? b. What should the (Pb"] be to just start precipitation? A town adds 20 ppm F ion to fluoridate its water supply. (Fluoridation of water reduces the incidence of dental caries.) If the concentration of Ca" in the water is 3.5 x 10* M, will a tate of CaF, form when the water is fluoridated? What would the concentration of F ion be to just start precipitation?

Explanation / Answer

1 a) K equilibrium constant for the reaction will be

K=[F-]2/[BaF2][SO42-]

b) On addition of Na2SO4 to saturated solution, then according to LeChatelier's Principle, the reaction will shift more to the product side, hence BaSO4 will then precipitate.