pH scale

How to find the concentration of H+ using pH equation

pH= -log (base 10) x [H+]

[H+]= 10^-pH

What is the most accurate way to measure pH

• Use a calibrated pH meter:: Directly reads the [H+'] concentration using electrode

• Use and Acid-Base indicator: Changes in different colours in solution according to the pH

what is Kw and when should it be used?

Kw represents the ionization constant of water

• Should be used when temp is at 298K or 25 degree C if trying to find concentration of OH or H

• Kw=[H+][OH-]

• Kw=[H+ ][OH- ]=(1.0×10^(-7) )(1.0×10^(-7) )=1.0×10^(-14)

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