when iron is rusted is there heat gain?

Expert Answers

An illustration of the letter 'A' in a speech bubbles

When iron and oxygen combine, rust forms. Iron can rust in contact with water, oxygen, or acids. Iron rusting is a redox reaction. Iron plus water plus air forms iron oxide or rust. Iron will lose electrons in this reaction and become a positively charged ion in water. The electrons that are lost are used to reduce the oxygen dissolved in water. The iron ions and the hydroxide ions that are negatively charged in water will react, to produce iron hydroxide. This eventually will form Fe2O3 or rust. When iron rusts, it is an exothermic reaction. This means that heat is released, however, in this particular reaction, it is occurring at a slow pace and a small amount of heat is released.

See eNotes Ad-Free

Start your 48-hour free trial to get access to more than 30,000 additional guides and more than 350,000 Homework Help questions answered by our experts.

Get 48 Hours Free Access
Approved by eNotes Editorial