Which quantities are conserved in all oxidation-reduction reactions?
A. Mass only.
B. Charge, only.
C. Both charge and mass.
D. Neither charge and mass.
E. Not applicable.
Matter can never be created or destroyed but it can change its form. Mass is always conserved in chemical reactions. Because the loss of electrons (by oxidation) must equal the gain of electrons (by reduction), charge must also be conserved. Only choice C includes conservation of charge and mass.