Find the H+ and pH of this please?

Supposing the missing unit on "0.756 HCl" to be "M":

HCl is a strong acid, so 0.756 M HCl = 0.756 M H{+}

pH = - log 0.756 = 0.121

If 0.756 is the molar concentration

Then the H+=0.756M

And the pH=0.12

Where the HCl is a strong electrolyte completely ionized so, all it's molecules are changed into ions.

That's why the [H+] is just as the original concentation and since pH is the -log[H+] so we just find the value by calculator.

Hope this helps.

HCl + H2O => H3O+ + Cl-

Since HCl is a strong acid, the amount of H+ or H3O+ produced is the same concentration as HCl

So [H+] = 0.756M

pH=-log[H+] = -log(0.756M) = 0.121