0.85 moles formula units of lead nitrate will produce 0.57 moles formula units of chromium (III) nitrate.
<h3>Explanation</h3>Typically, the oxidation state of Pb in lead nitrate tend to be +2. In other words, Pb in lead nitrate tends to exist as ions. The formula for a nitrate ion is
. The charge on each of the nitrate ion is -1. The charge on the two ions should balance. As a result, each
ion in lead nitrate would pair up with two
ions. The formula for lead nitrate will be
. Each formula unit of lead nitrate will contain one
ion and two
ions.
The "III" in the name "chromium (III) nitrate" is a Roman Numeral. It indicates that the oxidation state of Cr in chromium (III) nitrate is +3. The Cr in that compound will exist as . Similarly, each
will pair up with three
ions. The formula for chromium (III) nitrate will be
. Each formula unit of chromium (III) nitrate will contain one
ion and three
ions.
0.85 moles formula units of lead nitrate will contain 0.85 × 2 = 1.7 moles of ions. Those nitrate ions will end up in 1.7 / 3 = 0.57 moles formula units of chromium (III) nitrate. As a result, the reaction will produce 0.57 moles formula units of chromium (III) nitrate.