What is the overall reaction equation for an alkaline hydrogen-oxygen fuel cell?

The overall reaction equation for an alkaline hydrogen-oxygen fuel cell is represented as 2H2 + O2 → 2H2O. This equation signifies the fundamental electrochemical process occurring in the fuel cell.

In an alkaline hydrogen-oxygen fuel cell, hydrogen gas (H2) reacts with oxygen gas (O2) to produce water (H2O) and release energy. This process occurs in two half-reactions: the oxidation of hydrogen at the anode, where hydrogen is converted into protons (H+) and electrons (e-), and the reduction of oxygen at the cathode, where oxygen combines with the protons and electrons to form water.

The beauty of this reaction lies in its efficiency, generating only water as a byproduct, which is vital for the environmental sustainability associated with fuel cell technologies. This overall reaction succinctly encapsulates the electrochemical transformation that occurs, highlighting the combination of hydrogen and oxygen to output water, a key aspect of fuel cell technology.

Other options represent half-reactions or intermediary steps within the fuel cell and do not capture the complete overall reaction. Therefore, the choice indicating 2H2 + O2 → 2H2O correctly encapsulates the primary reaction happening in an