Question

1) 20.0 mL of 0.01 M AgNO3 and 30.0 mL of 0.010 M K2CrO4 are mixed together and allowed to react. Will a precipitate form? What will be the molarities of the silver ion and chromate ion at equilibrium?

2) Tooth enamel is composed of hydroxyapatite, whose simplest formula is Ca5(PO4)3OH and whose corresponding Ksp = 6.8 x 10^-27. As discussed, fluoride in fluorinated water or in toothpaste reacts with the hydroxyapatite to form fluoroapatite, Ca5(PO4)3F whose Ksp = 1.0 x 10^-60.

a) write the expression for the solubility constant for hydroxyapatite and for fluoroapatite.

b) calculate the molarity of each of these compounds.