what happens when HCl comes in contact with water?

Question

anonymous · Answer

H and Cl dissociate and become free ions in solution and the pH gets lowered.

sriram · Answer

how does the pH get lowered?
is it bcoz the concentration of H+ decreases??

anonymous · Answer

The concentration of H+ increases which causes the pH to lower. If a solution has a pH lower than 7 it is more acidic and vice versa if it is above 7 it is basic.

For example, let's look at the mathematical equation that tells us pH and play with the numbers.

Let's look at a [H+] of 10^-3
$$-\log(10^{-3}) = pH = 6.91$$

Now let's increase the concentration to [H+] of 10^-2
$$-\log(10^{-2}) = pH = 4.61$$

When you increase the concentration, the pH lowers. 

Hope that helps!

anonymous · Answer

To add onto what Eddoson said, the pH is the -log[H+]. Just wanted to clarify that for you.

anonymous · Answer

what acid/compound does it produce?

anonymous · Answer

The HCl dissociates into H+ (which actually reacts with a water molecule to form H30+] and Cl-.