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Lewis/ bronsted acid/ base

I'm getting a bit confused. Here we can see the water has accepted a proton so we can all it jronsted lowry base or Lewis acid but if we look to the right of the arrow there is an arrow showing the dative covslent bond and how the electron pair has gone from the oxygen to the hydrogen ..so the electron pair is being donated from the oxygen to the hydrogen so now it looks like the water is a bronsted lowry acid ...eh ..I'm getting rather confused

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(edited 10 years ago)

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Reply 1

BJack

Water can be viewed here as either a Bronsted-Lowry base, or as a Lewis base; it's certainly not a BL acid or Lewis acid!

• Bronsted-Lowry base: water accepts a proton.
• Lewis base: water donates an electron pair.

Reply 2

CasualSoul

Original post by BJack

Thanks - made me realise that I had my definitions mixed up

Cool avatar by the way :rofl:

Reply 3

BJack

Original post by charco

H₂O + H₂O --> H₃O+ + OH-

The first water molecule on the left hand side donates a proton. It is a BL acid ...
The second water molecule on the left hand side accepts a proton. It is a BL base ...

Water is both an acid and a base by the Bronsted Lowry (and Arrhenius) definitions.

Yes, that's right. But *here*, as in the OP's example, water is only acting as a base.

I don't see what you mean about it not being a Lewis base; it's using a lone pair to accept the proton. :s-smilie: