Final answer:
The mass fraction of eutectoid ferrite in an iron-carbon alloy considers the composition of eutectoid ferrite itself. During iron refining, carbon acts as a reducing agent to convert iron oxide into iron. Iron oxide is a compound of iron and oxygen atoms bonded by ionic bonds.
Step-by-step explanation:
To find the mass fraction of eutectoid ferrite in an iron-carbon alloy, we consider the composition of eutectoid ferrite. An alloy is a homogeneous mixture of two or more elements, with at least one of them being a metal. Steel is an example of an alloy made mainly from iron with a small percentage of carbon. The composition of eutectoid ferrite specifically relates to carbon content at 0.76% by weight in the alloy, which forms a characteristic microstructure at a specific temperature, in the case of steel, around 723°C.
During the refining of iron, carbon is necessary in the blast furnace to convert iron oxide into iron. Carbon acts as a reducing agent, removing oxygen from the iron oxide (Fe2O3), and allows the extraction of pure iron. This process is integral in the production of steel.
Iron oxide is comprised of iron and oxygen atoms, with iron being the metal component. The iron and oxygen atoms are bound together by ionic bonds to form the compound iron oxide, Fe2O3.