Four students attempt to draw a particulate diagram for an aqueous solution prepared…

CHEMISTRY · Single correct · AP · Chemistry · Properties of Substances and Mixtures · Properties of Substances and Mixtures

Problem

Four students attempt to draw a particulate diagram for an aqueous solution prepared by dissolving

\text{CaCl}_2(s)

. Which description best depicts a correct diagram? (a) The box contains twice as many

\text{Cl}^-

ions as

\text{Ca}^{2+}

ions; the hydrogen ends of the surrounding water molecules point toward each

\text{Ca}^{2+}

ion, and the oxygen ends point toward each

\text{Cl}^-

ion. (b) The box contains equal numbers of

\text{Ca}^{2+}

and

\text{Cl}^-

ions; the oxygen ends of water molecules point toward the

\text{Ca}^{2+}

ions and the hydrogen ends toward the

\text{Cl}^-

ions. (c) The box contains twice as many

\text{Cl}^-

ions as

\text{Ca}^{2+}

ions; the oxygen ends of surrounding water molecules point toward each

\text{Ca}^{2+}

ion, and the hydrogen ends point toward each

\text{Cl}^-

ion. (d) Clusters consisting of one

\text{Ca}^{2+}

ion and two

\text{Cl}^-

ions remain together as neutral units, with water molecules randomly oriented around each cluster.