1. Understanding Logarithmic Functions
Connections with Chemistry

2. Logarithmic Functions
The parent function f(x)=log x would result in negative values between 0 and 1.
We reflect the graph over the x axis to have positive values since pH is 1-14.
7 is neutral.
<7 is acidic.
>7 is basic.

3. Logarithmic Functions
f(x) = -logx
f(x) = logx
pH is derived from looking at the values from 0 to 1

4. A close up look at f(x) = - logx
A pH of 1 has a molarity of 0.1. pH
molarity

5. A close up look at f(x) = - logx
A pH of 2 has a molarity of 0.01 pH
molarity
The higher amount of H+ ions in moles/liter will result in a more acidic solution.

6. A close up look at f(x) = - logx
A pH of 4 has a molarity of pH
A pH of 3 has a molarity of 0.001
molarity

7. A close up look at f(x) = - logx
A pH of 6 has a molarity of pH
A pH of 5 has a molarity of
molarity

8. A close up look at f(x) = - logx
A pH of 14 has a molarity of e-14
or x pH
A pH of 13 has a molarity of e-13 or x
molarity

9. Find the H+ given the pH 9.17 basic 3.35 acidic 11.15 basic
Round to the nearest hundredth and determine if it is acidic or basic.
basic
acidic
basic
acidic

10. Given the pH, find the H+
If you have a pH of 8.3, what is the H+ concentration?
8.3= -log(x)
8.3= -log10(x)
-8.3=log10(x)
10-8.3=x x=

11. Given the pH, find the H+ 0.00398 or 3.948 x 10 -3
2.4
3.7
8.4
6.2
10.1
or x 10 -3
or x 10 -4
or 4 x 10 -9
or 6.31 x 10 -7
or 7.94 x

12. Summarize
Between what 2 whole numbers can the range of the H+ concentration be found?
Describe molarity and why we use those 2 numbers.
Why do we use the negative log function rather than the log function?