Fundamental question on acids/bases

[Hahzist]

Hello - I have been taking online courses on chemistry purely out of curiosity. I am having a hard time understanding how acids work on a very fundamental level.

I understand the PH scale, titration equations, how acids and bases behave on a molecular level.

So lets say I have HCl in an aqueous solution. From what I understand the hydrogen breaks off very easily from Chlorine, hence why it is a strong acid and basically you then have H3O+ hydronium ions floating around with Cl- ions. So the more hydrogen ions you have the stronger the acid. Why aren’t the Cl- ions essentially neutralizing the hydrogen ions overall since their the same opposite charge?  What is exactly going on that is giving something acidic properties (sour taste, corrosive, etc)? What am I missing? I imagine whatever the answer is, the same is true of bases? 

Thanks for any insight on this!

Edited March 29, 2019 by Hahzist

[chenbeier]

If you look from outside the electrical charges are neutral, because every H⁺ is neutralized by a Cl^-.  The reaction what is going on is solvation with the water, were H₂O attract H⁺ to a H₃O⁺. 

[John Cuthber]

Imagine we drop some zinc into the solution of HCl.

It dissolves + produces hydrogen

Zn + 2 H⁺ --> H₂ + Zn²⁺

The Cl^- simply isn't involved in the reaction, so it can't "neutralise" anything.

 

[Bufofrog]

47 minutes ago, John Cuthber said:

The Cl^- simply isn't involved in the reaction, so it can't "neutralise" anything.

I think he was saying that there are the same number of negative and positive ions, so the solution is electrically neutral.  Not sure why he thinks that matters, it certainly doesn't have anything directly related to the pH or the disassociation of acids.

[Dickson]

You should understand that pH measures the concentration of hydrogen ions. You are mixing the 2 concepts here. HCl(aq) can be said to be neutral with respect to charges. We have an equal number of positive and negatively charged ions, therefore the net charge is zero. However when you refer to pH, you are trying to measure the acidity of the solution. The acidity corresponds to the concentration of hydrogen ions. In water, HCl ionizes to form mobile hydrogen and chloride ions. This give rise to the lower pH.