Lycoming College                                         Quiz 5                                                   Write name on back

Chem 110, 2002                                                                                                                       upper right.

1.      Determine the sodium ion concentration and total ion concentration in a solution of Na₃PO₄ that is

0.0145 M Na₃PO₄.

Na⁺ concentration = ______________;  total ion concentration = ___________________

2.   Indicate whether each of the following is a strong electrolyte, weak electrolyte, or non-electrolyte.

a.       CH₃CH₂OCH₂CH₃            ______________________________

b.      Mg(NO₃)₂                          ______________________________

c.       KOH                                 ______________________________

d.      HI                                      ______________________________

e.       C₆H₅COOH                        _____________________________

3.     When an aqueous solution of copper(II) nitrate (Cu(NO₃)₂) is mixed with a solution of sodium sulfide (Na₂S), a brown-black insoluble precipitate forms.  Deduce the formula of the precipitate, and write balanced ion and net ionic equations to represent the chemical reaction.

Ionic Equation:

Net Ionic Equation:

4.   Indicate the oxidation state of

            a.   Mn in MnO₄^1-  __________;     b.  Mn in MnO₂  ___________;  c.  Cr in BaCrO₄ _________

5.   Balance the following redox equation:

            ____SeO₃^2-     +   ____I^1-      +   ____ H⁺       à     ____Se      +     ____ I₂    +   ____H₂O