CHEM 1A03 Study Guide - Final Guide: Iron(Iii) Oxide, Thermite, Thermodynamic System

• School: McMaster University
• Department: Chemistry
• Course: CHEM 1A03
• Professor: David J.H.Emslie

Document Summary

Iron will react with oxygen to produce rust, iron (iii) oxide. This reaction will occur without the input of any additional energy (spontaneous) If a reaction or process is spontaneous in forward direction, reverse process is non- spontaneous. So iron (iii) oxide will not decompose back to iron and oxygen on its own. In fact, we recover iron from iron(iii) oxide by reacting it with elemental carbon, which removes oxygen in the form of co2. We see spontaneity in physical changes like ice melting. At temps above 0oc ice will melt spontaneously into water. We do(cid:374)"t o(cid:271)ser(cid:448)e the re(cid:448)erse pro(cid:272)ess, (cid:449)ater freezi(cid:374)g spo(cid:374)ta(cid:374)eously i(cid:374)to i(cid:272)e a(cid:271)o(cid:448)e 0oc. It is not impossible for a non-spontaneous reaction or process to occur. Both spontaneous and non-spontaneous processes are possible, but only spontaneous processes will occur without intervention. Non-spontaneous processes require the system to be acted on by an external agent, such as input of energy.