Question #a6045

1 Answer
Jul 27, 2017

Water is both a Bronsted-Lowry acid and base.


According to Bronsted-Lowry theory, an acid is a proton donor whilst a base is a proton acceptor.

Consider the ionisation of water below:

#"H"_2"O" +"H"_2"O" rarr "H"_3"O"^(+) + "OH"^(-)#

As you can see, one water molecule donates its proton to the other to become a base whilst the other molecule accepts a proton to become an acid.

Therefore, we say that water is amphiprotic, meaning that it acts as both a Bronsted-lowry acid and base.