What kind of reaction is the 'water-splitting' reaction? H2O(l)¡H2(g) + ½ O2(g) (a) an acid-base reaction (b) a metathesis reaction (c) a redox reaction (d) a precipitation reaction

Redox reactions, or reduction-oxidation reactions, involve the transfer of electrons between substances. In these reactions, one species is oxidized (loses electrons) while another is reduced (gains electrons). The water-splitting reaction demonstrates this as water (H2O) is split into hydrogen gas (H2) and oxygen gas (O2), with oxygen being oxidized and hydrogen being reduced.

Oxidation states are a way to keep track of electron transfer in redox reactions. Each atom in a molecule is assigned an oxidation state based on its electron count relative to its elemental form. In the water-splitting reaction, the oxidation state of oxygen increases from -2 in H2O to 0 in O2, indicating that it has been oxidized, while hydrogen's oxidation state decreases from +1 to 0, indicating reduction.

Electrolysis is a process that uses electrical energy to drive a non-spontaneous chemical reaction, such as the water-splitting reaction. In this context, an electric current is applied to water, causing it to decompose into hydrogen and oxygen gases. This process is fundamental in various applications, including hydrogen production for fuel cells and energy storage.