A saturated solution of is initially at pH 7

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

Problem

A saturated solution of

\text{CaF}_{2}

is initially at pH 7. Which statement best describes the qualitative effect of raising the pH to 12? (a) The salt becomes more soluble because

\text{F}^{-}

ions are protonated to form

\text{HF}

. (b) The solubility is essentially unchanged because

\text{CaF}_{2}

is a salt of a strong acid and a strong base. (c) The salt becomes less soluble because fewer

\text{F}^{-}

ions are protonated at high pH. (d) The salt becomes more soluble because

\text{Ca}^{2+}

ions precipitate as

\text{Ca(OH)}_{2}

, removing

\text{Ca}^{2+}

from solution.