CORRECT


(5.a) NO PRECIPITATION WILL OCCUR

CaCl2(aq) + Na2SO4(aq) ---> CaSO4(s) + 2NaCl(aq)

Ca+2 + 2Cl- + 2Na+ +SO4-2---> CaSO4 + 2Na+ + 2Cl-

Ca+2 + SO4-2 ---> CaSO4

Since the Ksp = [Ca+2][SO4-2] = 2.4 x 10-5 M, whenever the product (Q) of the concentrations exceeds the Ksp, precipitation should occur.

Q = [Ca+2][SO4-2]

Q = (0.00005 moles/0.100L ) x (0.0005 moles/0.100 L)

Note: By mixing the solution you have to use total volume and the concentrations are lowered (dilution).

Q = [ 5 x10-4] [5 x 10-3]

Q = 2.5 x 10-6 M

Since the value of Q is less than Ksp then no precipitate will form.

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