An iron nail weighing 40.0 g is placed in 200.0 g of copper(II) sulfate, which reacts to form pure copper and iron(III) sulfate by the following reaction: __Fe(s) + __CuSO4(s) → __Fe2(SO4)3(s) + __Cu(s)
a. Fill in the missing coefficients to balance the equation.
b. What is the limiting reagent and the mass of iron(III) sulfate that is formed?
c. After the reaction goes to completion, what is the mass of the reactant that remains?

chemical changes occur when a substance combines with another to form a new substance, called chemical synthesis or, alternatively, chemical decomposition into two or more different substances. these processes are called chemical reactions and, in general, are not reversible except by further chemical reactions. some reactions produce heat and are called exothermic reactions and others may require heat to enable the reaction to occur, which are called endothermic reactions. understanding chemical changes is a major part of the science of chemistry.