Balancing formulas -- Worksheet
Name ______________________________Period _____ Date ___________________
The charges of many monatomic ions can be deduced by the location of the elements in the periodic table. Group 1 elements tend to form ions with a +1 charge; Group 2, +2; Group 13, +3; Group 15, -3; Group 16, -2; Group 17, -1. Memorize the charges on polyatomic ions.
What are the predicted charges on the following ions?
Mg _____
N _____
Al _____
Na _____
Li _____
Ca _____
O _____
F _____
Cl _____
S _____
NO3 _____
SO4 _____
PO4 _____
CO3 _____
NH4 _____
OH _____
ClO3 _____
MnO4 _____
C2H3O2 ____
CrO4 _____
Charged ions don't usually exist in isolation. They only form when they can be balanced by ions of opposite charge. The positive and negative charges must balance. Subscripts are used to balance the charges of the formula units of ionic compounds. Remember: the positive ion is always listed first in an ionic compound formula.
Predict the compounds that will form by a reaction of the following sets of ions. Balance the compound formulas.
Mg and Cl __________
O and Mg __________
Na and OH __________
NO3 and Ca __________
Ca and CO3 __________
Li and SO4 __________
PO4 and K __________
NH4 and OH __________