[cvc121]

Do strong acids dissociate into ions in water and weak acids do not? If so, if a strong acid such as HNO₃ is placed in water, what does it dissociate into? Is it H₃O⁺ and NO₃^- (this is what I think)? Or H⁺ and NO3^-?

Here is an example:
Nitric acid and potassium hydroxide are mixed. List the chemical species and determine the acid-base reaction that occurs.

Here is my attempt:

Chemical species are H₂O, H₃O⁺, NO₃^-, K⁺, and OH^-.
Then I figured out my strongest acid to be H₃O⁺ and strongest base to be OH^-.
Hence, my equation is H₃O⁺ + OH^-  H₂O + H₂O.
Are the chemical species I listed correct? Is the reaction correct as well?

Thanks! All help is very much appreciated!

[Hunter2]

Looks ok for me. H⁺ and H₃O⁺ is at least the same.

[Borek]

Do strong acids dissociate into ions in water and weak acids do not?

They both dissociate, just to a different degree. Strong acids dissociate almost completely (ie, all molecules are dissociated) while weak acids dissociate only partially.

if a strong acid such as HNO₃ is placed in water, what does it dissociate into? Is it H₃O⁺ and NO₃^- (this is what I think)? Or H⁺ and NO3^-?

H⁺ and H₃O⁺ are equivalent. What is happening is that acid - when dissociates - gives away its proton, which is accepted by a lone pair on the water molecule (actually this is even more complicated, and H₃O⁺ is only a model).