Why does the oxygen atom in H3O+ have a positive formal charge?

[semc]

Acid dissociates in water to form H₃O⁺ and OH^- but the formal charge on the oxygen atom in H₃O⁺ is +1. Shouldn't the oxygen atom have a negative formal charge since it is more electronegative than hydrogen atom?

 

[Borek]

Acid dissociates in water to form H₃O⁺ and OH^- but the formal charge on the oxygen atom in H₃O⁺ is +1. Shouldn't the oxygen atom have a negative formal charge since it is more electronegative than hydrogen atom?

Acids don't dissociate into H₃O⁺ and OH^-, formal charge of oxygen in H₃O⁺ is not +1 - so I have no idea what you are asking about.

-2 + 3*(+1) = +1

 

[semc]

I meant to ask the acid dissociation in water into H⁺ and A^-. So I wanted to ask why this is so. Why can't the acid accept the proton. Is this just because of the definition of acid?

 

[Borek]

Substance that accepts proton is called a base. See Brønsted-Lowry theory.