# Redox Reactions --- A **redox reaction** is a paired [[chemical reaction]] where an [[atom|electron]] is transfered from one substance to another. The substance losing the electron is being oxidized, and the substance gaining the electron is being reduced. These reactions are always paired, you can't oxidize one thing without reducing another, and vice versa. ![[redox.png]] ## Oxidation **Oxidation** is the *loss* of [[atom|electrons]] in a redox reaction (in other words, it becomes more positivly charged). During oxidation, bonds are *broken*. If a substance *looses* an electron, it has been *oxidized* If a substance can cause another substance to lose an electron, it is *oxidative* or oxydizing*, and is know as an *oxidizing agent*, *oxidant*, or an *oxidizer*. The oxidant strips the electron for itself, and is thus reduced. ### Oxidation State An atom or ion's oxidation state in a compound tells you how oxidated that atom is. It can be expressed as a superscript in arabic numerals, or when it is written out with the oxidation state in roman numerals in parenthesis after the name. For example, iron(II) sulfate or iron(III) sulfate. It is only expressed like this when there is a possiblity to have more than one oxidation state (like in iron). ## Reduction **Reduction** is the *gain* of [[atom|electrons]] in a redox reaction (in other words, it becomes more negativly charged). During reduction, bonds are *created*. If a substance *recieves* an electron, it has been *reduced*. If a substance can cause another substance to gain an electron, it is *reductive* or *reducing*, and is known as a *reducing agent*, *reductant*, or *reductor*. The reductant donates the electron from itself and is thus oxydized. reduction | oxidation --------- | --------- gain of electrons | loss of electrons becomes more negative | becomes more positive makes bonds | breaks bonds is reduced | is oxidised -----------| ----------- attracts hydrogens | looses hydrogens gets bigger | gets smaller reduces | oxidizes ------- | -------- causes reduction | causes oxidation makes bonds | breaks bonds is a reducing agent | is an oxidizing agent ### Reducing Power **Reducing power** is the potential of a substance to reduce another substance. Food has a lot of reducing power. ## Redox and Protons Sometimes "reduction" can seem to refer to gaining a [[hydrogen ion|proton]], and "oxidation" can seem to refer to losing a proton. This does happen (such as with electron carriers like NAD+ and NADH), but the real key is that the electron goes with the proton. ___