Chemistry learners are often troubled with topics related to reaction stoichiometry. The inspection method for balancing chemical equations is a trial-and-error process, which can be used only for simple chemical equations. Therefore, we discuss a uniform algebraic approach for balancing chemical equations and checking their inexactness, if any. In this method, arbitrary coefficients (say a, b, c, d …) are assigned to the individual reactant and product molecules. Different linear equations involving the coefficients are derived by using the law of conservation of mass. The derived equations are solved in terms of the assumed common coefficient (say a), which yields the values of the other assigned stoichiometric coefficients. Finally, the chemical equation is balanced by substitution of these values. It is interesting to note that there are no unique solutions of the coefficients for chemical equations wherein the number of assigned coefficients is more than the number of derived equations by two or more. For ionic redox reactions, the charges of the ionic species involved are also considered for expressing some of the coefficients in terms of the assumed coefficient. The inexactness of a chemical equation is ascertained when at least one of the coefficients is negative or zero.
Bhat et al. (Thu,) studied this question.