what is the concentration of HCl with pH 3.55
ph = -log(H3O) which we assume will equal the HCl concentration as it is completely ionized
3.55 = - log (H3O)
10^(-3.55) = [H3O] = 10^(-3.55) = 0.0002818382931264 = 2.818 x 10^(-4) M
+37165 
