Balanced equation for iron and copper (II) sulfate solution

What does x represent in the formula for the compound xcl4?

Which statement describes james chadwick’s discovery.

16. in a reaction that has reached equilibrium, a. the forward and reverse reactions are occurring at the same rate. b. the reactants and products are in equal concentrations. c. the forward reaction has gone further than the reverse reaction. d. there are equal numbers of atoms on both sides of the equation. e. a, b, and d are correct.