Balancing Chemical Equations Video Lessons

Concept: Balancing Chemical Reactions

# Problem: Lead (II) nitrate reacts with potassium iodide to form lead (II) iodide and potassium nitrate. Write the balanced equation for this.

###### FREE Expert Solution

We must first convert from a word equation to a symbol equation before writing the balanced reaction equation:

Lead (II) Nitrate + Potassium Iodide → Lead (II) Iodide + Potassium Nitrate

In lead (II) ion, the roman numeral II corresponds to a +2 charge, whilst the nitrate ion is NO3. To balance the charges, we require two nitrate ions per lead (II) ion, and so lead (II) nitrate is Pb(NO3)2.

The potassium ion is K+ has charge of +1 as it is from group 1A and the iodide ion has a charge of -1 because it is from group 7A, the two charges balance in a 1:1 ratio, so potassium iodide is simply KI.

In lead (II) iodide, the lead is Pb2+ and the iodide is I and the charges balance in a 1:2 ratios, so the formula is PbI2.

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###### Problem Details

Lead (II) nitrate reacts with potassium iodide to form lead (II) iodide and potassium nitrate. Write the balanced equation for this.