- What ions would you find in solution if potassium perchlorate was dissolved in water?
A. KCl, O 2
B. K+, Cl–, O2–
C. KCl, O2–
D. K+, ClO 4 –
E. K+, Cl–, O2–Answer: D
Potassium is a metal, and the polyatomic anion, ClO 4 – is a nonmetal; therefore, the compound
is an ionic solid at room temperature. When the compound is dissolved in water, the ionic bond
between the cation, K+, and the polyatomic anion, ClO 4 – , is broken due to the polarity of the
water molecule, resulting in the two aqueous ions, K+and ClO 4 –.
- Which one of the following is correct?
A. KClO 3 potassium perchlorate
B. CuO copper oxide
C. Al 3 (SO 3 ) 2 aluminum sulfate
D. MgPO 4 magnesium phosphate
E. Na 2 Cr 2 O 7 sodium dichromateAnswer: E
In choice A, KClO 3 is potassium chlorate, not perchlorate. In choice B, CuO is copper (II)
oxide, to distinguish it from copper (I) oxide, Cu 2 O. In choice C, the formula for aluminum
sulfate is Al 2 (SO 4 ) 3. In D, the formula for magnesium phosphate is Mg 3 (PO 4 ) 2. If you missed
these, review inorganic nomenclature and refer to pages 94 and 95 of this book to become fa-
miliar with common ions and their charges.
Ionic Bonding