Q:

What causes rust?

A:

Quick Answer

Rust is the product of a chemical reaction in which iron oxidizes in the presence of an electrolyte. In order to form iron oxide, exposed iron must bond with oxygen, which usually happens when the iron surface gets wet.

Know More

Full Answer

Oxidation is a chemical reaction in which electrons pass from a donor atom, called an anode, to a recipient atom, called a cathode, through an electrolyte. Iron is highly conductive, so it is capable of acting as both cathode and anode in an oxidation reaction. When water falls as rain, it takes up carbon from the atmosphere and becomes a weak form of carbonic acid. This acid begins dissolving iron as soon as it comes into contact with a ferrous surface. This creates a thin electrolyte soup that facilitates the passage of electrons from some iron atoms, the anodes, to the cathodes. During this transfer, iron atoms are eager to bond with oxygen, which forms large molecules of iron oxide, or rust. Iron oxide molecules are much larger than iron molecules alone, so the resulting patina of rust cannot adhere to the underlying layer of iron and rapidly flakes off. This exposes fresh iron to be oxidized in turn until the entire surface has been corroded.

Learn more about Chemistry

Related Questions

  • Q:

    What is the Haber process?

    A:

    The Haber process is a chemical reaction in which diatomic nitrogen gas reacts with hydrogen gas to form ammonia. The reaction equation is: N2 + 3H2 --> 2NH3. Although this reaction looks deceptively simple, the Haber process generates ammonia only under conditions of high pressure and temperature, on the order of 200 atmospheres and 400 degrees Celsius. Iron oxides or osmium can act as catalysts to speed up the reaction.

    Full Answer >
    Filed Under:
  • Q:

    What type of simple chemical reaction occurs in fireworks?

    A:

    A simple type of chemical reaction in fireworks is the color produced during and after the explosion. Chemical elements, generally metals, are mixed in with the gunpowder to create colors that vary depending on the element.

    Full Answer >
    Filed Under:
  • Q:

    What does hydrochloric acid and magnesium make?

    A:

    The chemical reaction between magnesium and hydrochloric acid produces magnesium chloride and hydrogen. The balanced chemical equation for this reaction is 2HCL(aq) + Mg(s) produces MgCl2(aq) +H2(g), where the subscripts refer to the substance's form, such as aq stands for aqueous, g is a gas, and s is a solid.

    Full Answer >
    Filed Under:
  • Q:

    What is the chemical formula for respiration?

    A:

    Respiration is a chemical reaction that can be expressed by the equation C6H12O6 plus 6O2 yields 6CO2 and 6H2O. This generally states that glucose and oxygen yield carbon dioxide and water. An aerobic reaction of this nature releases approximately 3,000 kilojoules per mole of material in the reaction.

    Full Answer >
    Filed Under:

Explore