Why is 1.0x10^-7 considered neutral?

[506200887]

Today in lecture we went from multiplying (1.0x10^-7) (1.0x10^-7) and getting the value 10^-14. I do not understand why you would assume that although the concentrations have to be equal for OH- and H3O+ why would it be 1.0x10^-7. Also it seems counter intuitive to start with the concentrations to prove that 7 is neutral on the pH scale.

[806145776]

I think that these are the values for water and based on the ph of water we have defined the pH scale causes almost all the reactions occur in water/ aqeous medium , so if the H+ ion conc is more than water then it is acidic and if it is more OH- than the amount water will produce then it is basic . The [OH-][H+] Conc are also related that they should be 10^-14 always , although I am bot completely clear why 10^-14 is constant .

[Nathaniel_Le_2J]

The value of 10^-14 is the constant because that’s the experimental value scientists have gotten from measuring the autoprotolysis of water at room temperature. For anybody of water at 25 degrees C with no acids or bases will have an H3O+ molarity of 10^-7 and an OH- molarity of 10^-7, kind of how any reaction will have a constant equilibrium constant at a given temperature no matter where it is.

[Daniel Chang 1K]

A pH of 1.0 * 10^-7 is considered neutral because it represents a perfectly balanced concentration of hydrogen ions (H+) and hydroxide ions (OH-) in a solution, typical of pure water at 25 degrees C.