DEFINITION!! PLZ 4 SCIENCE FAIR!!!
2007-01-22 07:47:36 · 4 answers · asked by Luv Is in the air 1 in Science & Mathematics ➔ Chemistry
Arrhenius, Bronsted, or Lewis version?
Arrhenius: Acid is anything that protonates (i.e. puts protons, H+, in) water (you can also say it produces hydronium ions, H3O+). Base is anything that puts hydroxide ions, OH-, in water.
Bronsted: Acid is anything that can donate a proton to another substance. A base is anything that can accept a proton from another substance.
Lewis: Acid is anything that can accept an electron pair from another substance. A base is anything that can donate an electron pair to another substance.
Keep in mind that the three aforementioned definitions of an acid do not mean that, say, a Lewis acid is a Bronsted acid. That simply isn't true. One substance may be an acid/base under one defintion and be something else under another.
Simplest, most boring definition: Acid is anything with pH below 7 or pOH above 7. Base is anything with pH above 7 or pOH below 7. A pH or pOH of 7 means a substance is neutral.
2007-01-22 07:54:24 · answer #1 · answered by infinitys_7th 2 · 0⤊ 0⤋
That depends highly on whose conventions you use.... there are several (at least seven) acid/base conventions.
To cut to the chase, there are two that stand out as most commonly used.
BRONSTED/LOWRY
The Bronstedt/Lowry definition of an acid is anything that donates a proton..... A proton donor.
Example: HCl donates a proton to water to become Cl-
Likewise, a base is a proton acceptor. Hydroxide ion (OH-)
accepts a proton to become water (H2O).
LEWIS
G. N. Lewis' concept is also widely used, and it can be advantageous over the B/L definition above, because it does not
require a proton to be present (to donate or accept). Instead, it operates in terms of electron pairs. A Lewis acid is an electron pair acceptor. (Example: BH3, which has vacant orbitals that can accept e' pairs.) A Lewis base is an electron pair donor. (Example: :NH3...notice the free electon pair it can donate/share with other compounds.)
Hope that gets you started. Good luck.
2007-01-22 07:56:22 · answer #2 · answered by ? 4 · 0⤊ 0⤋
According to Bronsted & Lowry "An Acid is a Proton donor and a Conjugate base is a proton acceptor" Neutrality is an arbitrary term-a solution having 0.0000001M Hydogen ion concentration(pH=7) .
2007-01-22 07:58:30 · answer #3 · answered by ssrvj 7 · 1⤊ 0⤋
ACID-a substance whose ph is BELOW 7
BASE-a substance whose ph is ABOVE 7
NEUTRAL-a substance whose ph is EXACTLY 7 (PURE water)
2007-01-22 07:56:38 · answer #4 · answered by Spearfish 5 · 1⤊ 0⤋