How do we represent the reaction between #"nickel(II) chloride"# and #"sodium hydroxide"# stoichiometrically?
I think you have already done it, mate.
All chemical equation CONSERVE (i) mass; and (ii) charge, and this is the principle of stoichiometry.......
In your given reaction, for every reactant particle, there is a corresponding product; charge is likewise conserved. And you have thus observed these principles.
The physical states of the reactants and products are something that you have to verify experimentally, but as written the equation is stoichiometrically balanced and sound.