Reductant

A **reductant**, also known as a reducing agent, is a substance that donates electrons in a redox (reduction-oxidation) chemical reaction. This donation causes the reductant itself to become oxidized, as it loses electrons. The reductant is therefore crucial in facilitating the reduction of another substance. The strength of a reductant is quantified by its tendency to lose electrons, quantified by its reduction potential. Stronger reductants readily donate electrons. The use of a reductant is fundamental across various fields from chemical synthesis to industrial processes.

Reductant meaning with examples

• In the famous reaction of copper(II) oxide with hydrogen, hydrogen acts as a reductant. It donates electrons to the copper(II) oxide, reducing the copper(II) to elemental copper, and becoming oxidized into water. This illustrates the fundamental role of a reductant in causing reduction.
• Sodium borohydride (NaBH₄) is frequently used in organic chemistry as a reductant to convert ketones and aldehydes into alcohols. It's a mild and selective reductant allowing specific modifications without causing unwanted reactions, making it vital for intricate synthesis.
• In ironmaking, coke acts as a reductant, reacting with iron ore (iron oxide) to remove oxygen and produce molten iron. This is a large-scale example where a reductant plays a crucial role in an industrial process with the carbon from the coke reducing the iron ore.
• During photography processing, the developer solution contains reductants like hydroquinone, which reduces the silver halide crystals in the film to metallic silver, creating the image. The reductant is key to image formation through a chemical process.