[Gammagirl]

What is the ph of 0.100 M CaCl2?

Is it ph=7
or
          CaCl2 + H2O----> 2HCl  +  Ca(OH)2
initial    0.100                    0             0
final         0                       0.200       0.100
[H+] = 0.200M  ph=-log 0.200=0.700

[Arkcon]

It's time to, in addition to doing math correctly, to use some logic.  This will save you on an exam from making a horrible mistake while you try to do all the work in the allotted time.

Therefore, Gammagirl:, a pH of less than 1, quite possibly the strongest acid you've ever seen, is it plausible a dilute solution of an ionic salt will produce such a solution?  What do you get from a 0.100 M NaCl solution?  You have that solid in your home, correct?  Can you dissolve your aluminum cookware with table salt?

[Gammagirl]

 The answer is ph=7. Can I have more examples excluding CaCl2 and NaCl?

[Borek]

KCl But for some other chlorides, like FeCl₃, solution will be substantially acidic (see the reaction written below for an idea of what is happening).

To be honest, pH of CaCl₂ is not 7, but finding the exact value can be quite challenging. First, Ca²⁺ reacts with water to some extent, lowering the pH:

Ca²⁺ + H₂O CaOH⁺ + H⁺

Second, pH changes because of the solution ionic strength. In the case of NaCl we can mostly ignore the reaction with water, but the ionic strength part still does change the pH. These things are probably beyond the chemistry level you are learning right now, but they make things a bit more complicated and not knowing your syllabus it is pretty difficult to say where is the line between the reality and what you are expected to know about it.