Presentation on theme: "Unit: Acids, Bases, and Solutions Calculations with Acids and Bases Day 2 - Notes."— Presentation transcript:
Unit: Acids, Bases, and Solutions Calculations with Acids and Bases Day 2 - Notes
After today you will be able to… Explain the correlation to strength of acids and bases to pH and pOH scale Calculate pH, pOH, [H + ], and [OH - ]
pH Scale pH scale: the measure of acidity of a solution pH=-log[H + ] acidic neutral 0714 basic [H+] = concentration in Molarity
Before we try an example, you will need to locate the “log” button on your calculator.
Example: What is the pH of a solution that has an [H + ]=1.5x10 -4 M? pH=-log[1.5x10 -4 ] pH=3.8
Example: What is the [H + ] in a solution with pH=9.42? 9.42=-log[H + ] -9.42=log[H + ] =[H+] [H+]=3.80x M To do this calculation you will need to use the inverse log. Locate the “10 x ” button. Usually it is the second function of the log button.
pH Scale pOH scale: the measure of alkalinity (basic-ness) of a solution pOH=-log[OH - ] acidic neutral 0714 basic
Example: What is the pOH of a solution that has an [OH - ]=3.27x10 -9 M? pOH=-log[3.27x10 -9 ] pOH=8.49
Since the pH and pOH scales are opposite each other: Example: What is the pH in a solution with a pOH=8.6? pH = 14 pH=5.4 pH + pOH = 14