Calcium fluoride has a solubility-product constant of at and at

CHEMISTRY · Single correct · AP · Chemistry · Acids and Bases · Acids and Bases

Problem

Calcium fluoride has a solubility-product constant of

2.0\times 10^{-11}

35\,^{\circ}\text{C}

and

5.0\times 10^{-12}

15\,^{\circ}\text{C}

. A chemist prepares

1.00\,\text{L}

of a solution saturated with

\mathrm{CaF_2}

35\,^{\circ}\text{C}

and then cools the solution to

15\,^{\circ}\text{C}

, keeping the volume constant. What mass of

\mathrm{CaF_2}

(molar mass

78.07\,\text{g/mol}

) will precipitate upon cooling? (a)

0.0078\,\text{g}

(b)

0.0050\,\text{g}

(c)

0.00050\,\text{g}

(d)

0.0084\,\text{g}