Presentation on theme: "PH and pOH Ways to measure Acidity/Basicity What is pH? What is pOH?"— Presentation transcript:
pH and pOH Ways to measure Acidity/Basicity What is pH? What is pOH?
What is pH? pH = potential Hydrogen The pH scale measures how acidic or basic a substance is, is logarithmic The pH scale ranges from 0 to 14. A pH of 7 is neutral. A pH less than 7 is acidic, greater than 7 is basic.
Basic Equations pH + pOH = 14 K w = [H+] [OH-] = 1 x
Calculating pH Values pH = 14 – pOH pH = - log [H+] Example: Calculate pH given [H+] = 1.4 x M pH = - log [H+] pH = - log [1.4 x ] pH = 4.85
Calculating [H + ] values EXAMPLE: Find [H+] if pH = 8.5 [H+] = 10 -pH [H+] = [H+] = 3.2 x M
Calculating pOH pOH = 14 – pH pOH = -log[OH-] EXAMPLE: What is the pOH of a solution that has a hydroxide ion concentration of 4.82 x M ? pOH = - log [OH - ] pOH = - log [4.82 x ] pOH = 4.32
YOU TRY! Find the pH of the solution if [H+] = 1 x M What is the hydrogen ion concentration if pH = 7.1? What is the pH if [OH-] = 4 x M? pH = = -log [H + ] 10 – 7.1 = [H + ] = 7.9 x M pOH = -log [OH-] pOH = -log [4 x ] =