![What is the pH of a solution in which the
concentration of H+ 3.4 x 10-5? Is the substance
acidic, basic, or neutral?
Solution:
pH = -log [H+]
= -log[3.4 x 10-5]
pH = 4.47
ACIDIC
NOTE: For Significant figures for
Logarithms
The number of decimal places
in the log is equal to the number
of significant figures in the
original number.](https://image.slidesharecdn.com/23-230212110724-63e1c5fd/85/23-pH-A-Measure-of-Acidity-pptx-4-320.jpg)
![1. Calculate the pH values. Determine if each solution is
acidic, basic, or neutral.
A. [H+] = 1 x 10-7 M
B. [H+] = 6.7 x 10-11 M
C. [H+] = 0.1 M
D. [H+] = 8.54 x 10-9 M
2. What is the Hydrogen Ion Concentration if the pH
equals
8.75?](https://image.slidesharecdn.com/23-230212110724-63e1c5fd/85/23-pH-A-Measure-of-Acidity-pptx-8-320.jpg)
![TRY THIS!
What is the pOH of a solution that contains
3.5 x10-5 [OH-]? What is the substance’s pH?
pOH = -log [OH-]
pOH = -log [3.45 x10-5]
pOH = 4.46
pH + pOH = 14.00
= 14.00 – 4.46
pH = 9.54](https://image.slidesharecdn.com/23-230212110724-63e1c5fd/85/23-pH-A-Measure-of-Acidity-pptx-10-320.jpg)
![TRY THIS!
In a NaOH solution [OH-] is 7.2 X 10 -5 M. Calculate
the pH of the solution.](https://image.slidesharecdn.com/23-230212110724-63e1c5fd/85/23-pH-A-Measure-of-Acidity-pptx-11-320.jpg)
![TRY THIS!
The OH- ion concentration of a blood sample is
2.5 X 10 -7 M. What is the pH of the blood?
pOH = -log [OH-]
pOH = -log [2.5 X 10 -7]
pOH = 6.60
pH + pOH = 14.00
= 14.00 – 6.60
pH = 7.40](https://image.slidesharecdn.com/23-230212110724-63e1c5fd/85/23-pH-A-Measure-of-Acidity-pptx-12-320.jpg)
![TRY THIS!
The pH of a sample of human blood was measured to
be 7.41 at 25⁰C. Calculate pOH, [H+], and [OH-] for
the sample.
OH- = 10-pOH
OH- = 10-6.59
OH = 2.6 X 10 -7 M
pH + pOH = 14.00
= 14.00 – 7.41
pOH = 6.59
H+ = 10-pH
H+ = 10-7.41
H+ = 3.9 X 10 -8M](https://image.slidesharecdn.com/23-230212110724-63e1c5fd/85/23-pH-A-Measure-of-Acidity-pptx-13-320.jpg)
23. pH - A Measure of Acidity.pptx
- 1. pH - A Measure of Acidity
- 2. pH- stands for potential of hydrogen. The pH of a solution is defined as the negative logarithm of the hydrogen ion concentration (in mol/L): The Danish chemist Soren Sorensen in 1909 proposed a more practical measure called pH. H+ ion concentration is asked, just take the antilog of the equation
- 3. The pH scale was developed in an effort of compare the strengths of acids and bases. The pH scale runs from 0-14 pH < 7 are acidic pH = 7 are neutral pH > 7 are basic
- 4. What is the pH of a solution in which the concentration of H+ 3.4 x 10-5? Is the substance acidic, basic, or neutral? Solution: pH = -log [H+] = -log[3.4 x 10-5] pH = 4.47 ACIDIC NOTE: For Significant figures for Logarithms The number of decimal places in the log is equal to the number of significant figures in the original number.
- 5. TRY THIS! The concentration of H+ ions in a bottle of table wine was 4.1 x 10-4 M right after the cork was removed. Only half of the wine was consumed. The other half, after it had been standing open to the air for a month, was found to have a hydrogen ion concentration equal to 2.3 x 10-3 M. Calculate the pH of the wine on these two occasions.
- 6. TRY THIS! What is the hydrogen ion concentration if pH is 3.30? H+= 10-3.30 H+= 5.0 x 10-4M
- 7. TRY THIS! The pH of rainwater collected in a certain region of the northeastern United States on a particular day was 5.23. Calculate the H+ ion concentration of the rainwater. H+= 10-5.23 H+= 5.9 x 10-6 M
- 8. 1. Calculate the pH values. Determine if each solution is acidic, basic, or neutral. A. [H+] = 1 x 10-7 M B. [H+] = 6.7 x 10-11 M C. [H+] = 0.1 M D. [H+] = 8.54 x 10-9 M 2. What is the Hydrogen Ion Concentration if the pH equals 8.75?
- 9. pOH - stands for potential of hydroxide ions. pOH measures the amount of hydroxide ions and measures basicity pH + pOH = 14.00 If asked to calculate the OH- ion concentration, we can take the antilog of Equation:
- 10. TRY THIS! What is the pOH of a solution that contains 3.5 x10-5 [OH-]? What is the substance’s pH? pOH = -log [OH-] pOH = -log [3.45 x10-5] pOH = 4.46 pH + pOH = 14.00 = 14.00 – 4.46 pH = 9.54
- 11. TRY THIS! In a NaOH solution [OH-] is 7.2 X 10 -5 M. Calculate the pH of the solution.
- 12. TRY THIS! The OH- ion concentration of a blood sample is 2.5 X 10 -7 M. What is the pH of the blood? pOH = -log [OH-] pOH = -log [2.5 X 10 -7] pOH = 6.60 pH + pOH = 14.00 = 14.00 – 6.60 pH = 7.40
- 13. TRY THIS! The pH of a sample of human blood was measured to be 7.41 at 25⁰C. Calculate pOH, [H+], and [OH-] for the sample. OH- = 10-pOH OH- = 10-6.59 OH = 2.6 X 10 -7 M pH + pOH = 14.00 = 14.00 – 7.41 pOH = 6.59 H+ = 10-pH H+ = 10-7.41 H+ = 3.9 X 10 -8M
- 14. Complete the following chart pH H+ OH- pOH 3.00 1.0 X 10 -10 M 11.50 5.2 X 10 -11 M
- 15. Complete the following chart pH H+ OH- pOH 3.00 1.0 X 10 -3 M 1.0 X 10 -11 M 11.00 10.00 1.0 X 10 -10 M 1.0 X 10 -4 M 4.00 2.50 3.2 X 10 -3 M 3.2 X 10 -12 M 11.50 3.72 1.9 X 10 -4 M 5.2 X 10 -11 M 10.28
- 16. Complete the following chart pH H+ OH- pOH 1.83 X 10 -10 M 5.5 2.2 X 10 -11 M 8.55
- 17. Complete the following chart pH H+ OH- pOH 9.738 1.83 X 10 -10 M 5.5 X 10 -5 M 4.26 5.5 3 X 10 -6 M 3 X 10 -9 M 8.5 3.34 4.6 X 10 -4 M 2.2 X 10 -11 M 10.66 5.45 3.5 X 10 -6 M 2.8 X 10 -9 M 8.55
- 18. Complete the following chart pH H+ OH- pOH 3.00 1.0 X 10 -3 M 1.0 X 10 -11 M 11.00 10.00 1.0 X 10 -10 M 1.0 X 10 -4 M 4.00 2.50 3.2 X 10 -3 M 3.2 X 10 -12 M 11.50 3.72 1.9 X 10 -4 M 5.2 X 10 -11 M 10.28
Editor's Notes
- #3: Because the concentrations of H1 and OH2 ions in aqueous solutions are frequently very small numbers and therefore inconvenient to work with, the Danish chemist Soren Sorensen in 1909 proposed a more practical measure called pH.
- #6: The increase in hydrogen ion concentration (or decrease in pH) is largely the result of the conversion of some of the alcohol (ethanol) to acetic acid, a reaction that takes place in the presence of molecular oxygen
- #7: pH=dec : SF H+
- #8: pH=dec : SF H+
- #9: 7 NEU 10.17 BAS 1 ACI 8.069 B 2. 1.8 X 10*-9
- #11: The increase in hydrogen ion concentration (or decrease in pH) is largely the result of the conversion of some of the alcohol (ethanol) to acetic acid, a reaction that takes place in the presence of molecular oxygen
- #12: The increase in hydrogen ion concentration (or decrease in pH) is largely the result of the conversion of some of the alcohol (ethanol) to acetic acid, a reaction that takes place in the presence of molecular oxygen
- #13: IN order o solve Ph, u need to solve for Poh first. SF 2.5 = 2
- #14: IN order o solve Ph, u need to solve for Poh first. SF 2.5 = 2