Chemical Forums

Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: mrge on February 11, 2010, 05:19:36 AM

Title: quick questions about redox reactons.
Post by: mrge on February 11, 2010, 05:19:36 AM

My chemistry teacher is a lil on the crazy side.. she doesn't explain it very well so i jsut read the book to understand it on my own. To my understanding.. redox reaction basically is the process when a chemical loses an electron (oxidation) and gains an electron (reduction) correct?

For example

Iron turning to rust

Half reaction of Iron (oxidation)

Fe

---

Fe^+3 + -3e

Half Reaction of Oxygen (reduction)

2O + -4e

---

2O^-2

My question is.. theres are rules for assigning oxidation numbers ( the number of electrons the chemical gives away ) which makes sense.. but how would you figure out the numbers of electrons gained by certain chemicals. My book shows only the oxidation rules in the chapter.. is there a way to figure out reduction numbers?

Title: Re: quick questions about redox reactons.
Post by: Borek on February 11, 2010, 07:22:52 AM

It is all about change - you calculate ON for reactant and product, and the difference in number of electrons, no matter if they are gained or given.