Question

What is the difference between Arrhenius, Bronsted-Lowry, and Lewis acids and bases?

Answer 1

Arrhenius => release of `H^+`/`OH^-` in aqueous solution

Bronsted-Lowry => donation/acceptance of proton

Lewis => acceptance/donation of electron pair

Explanation:

The definition of acid and base according to the three acid-base theories are:

Arrhenius acid-base theory

• acid - a substance produces hydrogen ions (`H^+`) in aqueous solution.
• base - a substance that produces hydroxide ions (`OH^-`) in aqueous solution.

Here's the general equation defining Arrhenius acid and base:

Bronsted-Lowry acid-base theory

• acid - proton (hydrogen ion) donor

• base - proton (hydrogen ion) acceptor

Here are examples showing general equation defining (a) acid and (b) base:

In (a), HA is an acid since it donates proton(`H^+`) to water. In (b), B is a base because it accepts proton (`H^+`)from water.

Lewis acid-base theory

• acid - electron pair acceptor

• base - electron pair donor

An example illustrating Lewis acid-base:

`BH_3` in the given example is a Lewis acid since it accepts the electron pair from `NH_3`
`NH_3`, in this case, is a Lewis base since it donates the electron pair.