Cracking the SAT Chemistry Subject Test

CHAPTER 9 SOLUTIONS

Drill 1

1. E When ionic solutes dissolve in water, an electrolytic solution is
   produced. Are there any ionic solutes among the choices? Look for the
   combination of a metal and a nonmetal. Sodium chloride is ionic, and (E) is
   the correct answer.


2. A When you are told that solubility increases as temperature
   decreases, think of dissolving a gas in aqueous solution. Are there any gases
   in the answer choices? Yes: NO 2 . The correct answer is (A).


3. E Remember that the degree of boiling point elevation is proportional
   to the moles of dissolved particles. Choices (A) through (D) are substances
   composed solely of nonmetals. They are molecular compounds. In general,
   molecular compounds don’t dissociate (acids, which we’ll look at later, are
   an important exception), so 1 mole of the substances in (A) through (D)
   gives 1 mole of dissolved particles. Sodium chloride is different. As it
   dissolves, NaCl dissociates into Na+ and Cl− ions, so 1 mole of NaCl yields
   2 moles of dissolved particles. NaCl is the solute that will most raise
   water’s boiling point; the correct answer is (E).


4. T, T Divide and conquer. Look at the first statement by itself. Is it true?
   Yes; you should associate “ions dissolved in solution” with the idea of
   conducting electricity.
   The second statement is true. When a solvent can’t
   dissolve any more solute, it’s saturated—the solute has
   reached the limit of its solubility. Let’s see whether the
   whole sentence makes sense. “Aqueous solutions with
   ionic solutes conduct electricity because a liquid
   solvent becomes saturated when the solute reaches the
   limit of its solubility.” The sentence is nonsense—do
   not fill in the CE oval.