Classification of Penicillin. 1  Natural Penicillins (Penicillin V, Penicillin G, Benzathine, Procaine Penicillin) 2  Penicillinase-Resistant Penicillins (Oxacillin, Dicloxacillin, Cloxacillin, Methicillin, Nafcillin) 3  Aminopenicillins (Amoxicillin, Bacampicillin, Ampicillin) 4  Extended Spectrum Penicillins.
the system is usually defined as the chemical reaction and the boundary is the container in which the reaction is run in the course of the reaction heat is either given off or absorbed by the system furthermore the system either does work on it surroundings or has work done on it by its surroundings
Chemical reactions describe the changes between reactants (the initial substances that enter into the reaction) and products (the final substances that are present at the end of the reaction).