What is produced by a galvanic cell as a result of the spontaneous reaction occurring inside it?

In a galvanic cell, a chemical reaction occurs spontaneously, generating an electric current as a result of this reaction. This process involves the transformation of chemical potential energy into electrical energy through redox reactions, where oxidation and reduction of reactants take place at different electrodes.

During the operation of the galvanic cell, electrons flow from the anode (where oxidation occurs) to the cathode (where reduction occurs), creating an electric current that can be harnessed to do work, such as powering electronic devices. The spontaneity of the reaction is characterized by a negative Gibbs free energy change (ΔG < 0), which is indicative of the system shifting towards equilibrium while producing electrical energy.

The other options may not arise from a galvanic cell's function in the way that electricity does. Heat can be produced due to resistive losses, but it is not the primary useful output. Hydrogen and oxygen gases can be products of specific reactions (such as in electrolysis), but they are not universally produced in all galvanic cells. Thus, the primary and significant product of a galvanic cell is electricity, which directly indicates the generation of power from the spontaneous reaction occurring within.