Roman numerals in a chemical formula indicate the charge on the metal cation before them. They are used in situations where the multiple oxidation states are available to the metal. For example, iron can be both 2+ and 3+, so to distinguish between the two, we use iron (II) and iron (III) respectively.
The Rate of formation of products depends on the concentration of reactants or the forward reaction increases on increasing the rate of the concentration.
There is no effect on the equilibrium rate when the concentration of reactants and products is constant.
Forward reaction slows down when the reactant concentration is decreased.
On increasing the amount or concentration of reactant the chemical equilibrium shifts towards formation of more products.
