When balancing reactions in Chapter 3 , we did not mention that reactions must be charge balanced as well as mass balanced. What do charge balanced and mass balanced mean? How are redox reactions charge balanced?

In a mass balanced reaction, the total number of atoms of each element remains the same before and after the chemical reaction, adhering to the principle of conservation of mass. In a charge balanced reaction, the total charge of the reactants equals the total charge of the products. Charge balance is particularly important for redox reactions, where there's an exchange of electrons between species, affecting the overall charge. Redox reactions maintain charge balance because the electrons lost by one species (the reducing agent) are gained by another species (the oxidizing agent). To balance charge in a redox reaction, identify the oxidation states of all species involved, calculate the overall charge for both sides, determine the number of electrons transferred, and balance the charge by adjusting the coefficients to ensure equal net charges.