Why don't bases react with metals while acids do?

Question

Why don't bases react with metals while acids do?

Answer 1

Using the Lewis theory of acids and bases, an acid is an electron pair acceptor, while a base is an electron pair donor.

Electrons are not tightly held in many metals, that is why metals conduct electricity. An acid accepts electrons easily, that is why it is an acid.

So when a metal that gives up electrons easily comes in contact with an acid that accepts electrons easily, the reaction is favored. The metal loses electrons (oxidizes), and the H+ ions of the acid accepts the electrons (reduces) to form hydrogen gas H2 that bubbles up.

A base is an electron pair donor. Both the metal and the base tend to give up electrons, and no preferred direction for the electrons to go, no reaction occurs.

Electrochemistry is the branch of chemistry that studies how easily electrons can be added or removed from elements and compounds in solution. Electrochemistry gets real complicated real quick. For more information see:

http://www.chem1.com/acad/webtext/elchem/ec3.html#EMS

The table at the top of this site shows metals in order of electron donating power. Those metals above hydrogen, will donate electrons to H+ ions to form hydrogen gas. Those metals below hydrogen, do not.

Answer 2

Some bases react with some metals in similar ways. For instance, a concentrated solution of sodium hydrox\de will dissolve aluminum in the same way that hydrochloric acid will dissolve zinc.

The main reason this doesn't happen all the time is because the attaking species must have a higher standard reduction potential than the species being attacked. This phenomena is more probable with acids than with bases because of the nature of the oxidation state of the central atom.

Answer 3

Bases React With

Answer 4

The H+ ion is much easier to reduce (to hydrogen gas) than the OH- ion!