Equations can be balanced by using the half-reaction method. which step should be completed immediately after finding the oxidation states of atoms? a; inserting the coefficients b; balancing the half reactions c; identifying the half reactions d; inspecting the number of atoms

After finding the oxidation states of atoms, you identify the half reactions (option c).

The half reactions are given by the change of the oxidation states of the atoms.

For example if Cu is in the left side with oxidation state 0 and in the other side with oxidation state 2+, then there you have a half reaction (oxidation reaction). And if you have O with oxidation state 0 in the left side  and with oxidation state 2- in the right side, there you have other half reaction (reducing reaction).

Molarity is moles of solute over liters of solution. idk if that is what you are talking about, but you can convert moles of solute to grams of solute using dimensional analyzes by using molar mass found on the periodic table.