Editing Reactivity series (section)

== Defining reactions ==

There is no unique and fully consistent way to define the reactivity series, but it is common to use the three types of reaction listed below, many of which can be performed in a high-school laboratory (at least as demonstrations).<ref name=":0" />

=== Reaction with water and acids ===

The most reactive metals, such as [[sodium]], will react with cold water to produce [[hydrogen]] and the metal [[hydroxide]]:

:2 Na (s) + 2 H<sub>2</sub>O (l) →2 NaOH (aq) + H<sub>2</sub> (g)

Metals in the middle of the reactivity series, such as [[iron]], will react with acids such as [[sulfuric acid]] (but not water at normal temperatures) to give hydrogen and a metal [[salt (chemistry)|salt]], such as [[iron(II) sulfate]]:

:Fe (s) + H<sub>2</sub>SO<sub>4</sub> (l) → FeSO<sub>4</sub> (aq) + H<sub>2</sub> (g)

There is some ambiguity at the borderlines between the groups. [[Magnesium]], [[aluminium]] and [[zinc]] ''can'' react with water, but the reaction is usually very slow unless the metal samples are specially prepared to remove the surface [[passivation layer]] of oxide which protects the rest of the metal. [[Copper]] and [[silver]] will react with [[nitric acid]]; but because nitric acid is an [[oxidizing acid]], the oxidizing agent is not the H<sup>+</sup> ion as in normal acids, but the NO<sub>3</sub><sup>−</sup> ion.