# Is sodium ion an acid?

As sodium ion has a 1+ charge and it can form the ionic compound NaOH with OH1-, hence it is a lone pair accepter (is this correct?). Therefore sodium ion should be an acid?

• Yes, it's a Lewis acid, but a weak one. – Mithoron Sep 15 '18 at 18:22
• But $\ce{Na+}$ isn't an acid in the Brønsted–Lowry theory, so it depends... – MaxW Sep 15 '18 at 23:33

## 1 Answer

According to the bronsted lowry definition of an acid, the sodium ion is not an acid. This is because the bronsted lowry definition of an acid states that an acid is a proton donor. The sodium ion is not a proton donor and so according to this definition it is not classed as an acid.

I hope this answers your question :)

• But the question doesn't specify Bronsted-Lowry. It actually has descriptions related to Lewis and Arrhenius acids, so the Bronsted-Lowry definition is the least related to the question. – SendersReagent Sep 26 '18 at 19:42
• But in water the ion will be hydrated, and the hydrated ion can most definitely act as a (weak) Bronsted-Lowry acid – Ian Bush Sep 26 '18 at 21:05