Answer Key

All values of pH, pOH, [H+], [OH-] can be found by using the formulas which are restated below and then entering these into a scientific calculator.  

pH = -log [H+]

[H+] = 2nd Fn log [ -pH]

pOH = -log [OH-]

[OH-] = 2nd Fn log [ -pOH] 

pH + pOH = 14

[H+][OH-] = 1x10-14 (1E-14)

1. 

pH = 6.65

pOH =  7.35

[H+] = 2.24 e-7

[OH-] = 4.46 e-8


2. 

pH = 2.65

pOH = 11.35 

[H+] = 2.24 e-3

[OH-] = 4.47 e-12


3. 

pH = 2.86

pOH = 11.14

[H+] = 1.4e-3

[OH-] = 7.24e-12


4. 

pH = 1.37

pOH = 12.63

[H+] = 4.27e-2

[OH-] = 2.34e-13


5. 

pH = 9.1

pOH = 4.9

[H+] = 7.76e-10

[OH-] = 1.26e-5
6. 

pH = 4

pOH = 10 

[H+] = 1.0e-4

[OH-] = 1.0e-10 


7.

pH = 3.4

pOH = 10.6

[H+] = 3.98e-4

[OH-] = 2.51e-11


8.

pH = 10.4

pOH = 3.6

[H+] = 3.98e-11

[OH-] = 2.51e-4


9.

pH = 6.79

pOH = 7.21

[H+] = 1.62e-7

[OH-] = 6.2e-8


10.

pH = 4.26

pOH = 9.74

[H+] = 5.49e-5

[OH-] = 1.82e-10