Adding water to acids, dilutes them.
Add ing 1 part water to 1 part pH2 acid, dilutes the acid to 1/2 its
H+, in free protons. Acids give extra protons.
Also each step you go in pH is 10x stronger/weaker.
A pH of 2 is H+ = 10,000; while a pH of 3 is H+=1000.
So 10,000/2 [after diluting by 1 part water] gives H+= 5000.
That is still within the pH2 acidic area, but is weaker in acidity than
before; yet is still stronger(more acidic) than pH of 3.
See table 1...here >>