How can I write dissociation equations?

1 Answer

To dissociate means to take apart.

When ionic compounds (compounds made from metals and non-metals) like sodium chloride #"NaCl"# or iron(III) sulfate #"Fe"_2("SO"_4)_3# are dissolved in water, they come apart into positive (metal) ions and negative (non-metal) ions.

When you write a dissociation reaction you separate the two ions, place their charges above their symbols, and then balance the entire equation.

For example, the dissociation of sodium chloride would look like this:

#"NaCl" → "Na"^+ + "Cl"^-#

The dissociation of iron(III) sulfate would look like this:

#"Fe"_2("SO"_4)_3 → 2"Fe"^(3+) + 3"SO"_4^(2-)#