logging in or signing up pH and the pH scale ariedl Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 1512 Category: Science & Tech.. License: All Rights Reserved Like it (3) Dislike it (0) Added: January 17, 2010 This Presentation is Public Favorites: 2 Presentation Description No description available. Comments Posting comment... By: amarjeet1212 (20 month(s) ago) sir i wnt dis ppt as it wil b very much helpful to u so sir .i wil b thankful to u sir.my email id is amarjeet1212@gmail.com Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript pH and the pH scale : pH and the pH scale by Ann Riedl, Ph.D., Biology Department, Front Range Community College What is pH? : What is pH? pH is a measure of the activity of hydrogen ions in a solution {H+} It approximates the molar concentration of hydrogen ions in a solution [H+] Slide 3: So, what are these hydrogen ions and why do we care so much about them? H+ H+ H+ H+ H+ H+ Slide 4: Hydrogen atoms consist of one positively charged proton with one negatively charged electron orbiting it H Slide 5: Remove the electron, and you are left with just a proton, or a positively charged hydrogen ion H+ Slide 6: It turns out proteins, such as enzymes, are very sensitive to the effects of hydrogen ions Too many or too few hydrogen ions in a solution can make a protein denature, or unfold, and stop working properly H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ Slide 7: If a solution has just the right concentration of hydrogen ions to make our proteins work well, it is called neutral If a solution has too many hydrogen ions, it is called acidic If a solution has too few hydrogen ions, it is called basic acidic neutral basic Slide 8: A substance that releases hydrogen ions when it is put into a solution is called an acid Cl- H+ Cl- H+ Cl- H+ Cl- H+ Cl- H+ Slide 9: A substance that removes hydrogen ions when it is put into a solution is called an base H+ H+ H+ H+ H+ H+ H+ OH- Na+ OH- Na+ OH- Na+ OH- Na+ H2O H2O H2O H2O Slide 10: The concentration of hydrogen ions [H+] is important to normal function of our cellular proteins Trouble is, the [H+] of most biological solutions is very low For example, pure water has a [H+] of .0000001 moles/liter, or, in scientific notation, 1 x 10-7 M No one, not even scientists, like to work with numbers this small Slide 11: So, the pH scale was developed to make it easier to keep track of those pesky H+ pH is the negative logarithm of [H+] Sounds complicated… but it simply means that you state the hydrogen ion concentration in scientific notation, take the exponent, and change its sign Thus water, rather than being [H+] 1 x 10-7, is simply pH 7 Slide 12: Let’s practice… 1. Lemon juice has a [H+] of 1 x 10-3 M What is the pH of lemon juice? 2. Household bleach has a pH of 13 What is the [H+] of household bleach? 3. Stomach acid has a [H+] of .01 M What is the pH of stomach acid? pH = 3 1 x 10-13 M = .0000000000001 M .01 M = 1 x 10-2 M pH = 2 Slide 13: Because scientific notation is in base ten, a change in one of the pH represents a ten-fold change in [H+] Because pH is the negative logarithm, an increase in pH represents a decrease in [H+] .000001 = 1 x 10-6 pH 6 .0000001 = 1 x 10-7 pH 7 .00000001 = 1 x 10-8 pH 8 Acids, Bases, and pH : Acids, Bases, and pH In summary, we use the pH scale to describe the [H+] of a solution by taking the negative logarithm of the actual [H+] pH 7 is arbitrarily described as neutral Solutions with pH below 7 have a higher [H+] and are therefore acidic Solutions with pH above 7 have a lower [H+] and are therefore basic The pH Scale : The pH Scale You do not have the permission to view this presentation. In order to view it, please contact the author of the presentation.
pH and the pH scale ariedl Download Post to : URL : Related Presentations : Share Add to Flag Embed Email Send to Blogs and Networks Add to Channel Uploaded from authorPOINT lite Insert YouTube videos in PowerPont slides with aS Desktop Copy embed code: (To copy code, click on the text box) Embed: URL: Thumbnail: WordPress Embed Customize Embed The presentation is successfully added In Your Favorites. Views: 1512 Category: Science & Tech.. License: All Rights Reserved Like it (3) Dislike it (0) Added: January 17, 2010 This Presentation is Public Favorites: 2 Presentation Description No description available. Comments Posting comment... By: amarjeet1212 (20 month(s) ago) sir i wnt dis ppt as it wil b very much helpful to u so sir .i wil b thankful to u sir.my email id is amarjeet1212@gmail.com Saving..... Post Reply Close Saving..... Edit Comment Close Premium member Presentation Transcript pH and the pH scale : pH and the pH scale by Ann Riedl, Ph.D., Biology Department, Front Range Community College What is pH? : What is pH? pH is a measure of the activity of hydrogen ions in a solution {H+} It approximates the molar concentration of hydrogen ions in a solution [H+] Slide 3: So, what are these hydrogen ions and why do we care so much about them? H+ H+ H+ H+ H+ H+ Slide 4: Hydrogen atoms consist of one positively charged proton with one negatively charged electron orbiting it H Slide 5: Remove the electron, and you are left with just a proton, or a positively charged hydrogen ion H+ Slide 6: It turns out proteins, such as enzymes, are very sensitive to the effects of hydrogen ions Too many or too few hydrogen ions in a solution can make a protein denature, or unfold, and stop working properly H+ H+ H+ H+ H+ H+ H+ H+ H+ H+ Slide 7: If a solution has just the right concentration of hydrogen ions to make our proteins work well, it is called neutral If a solution has too many hydrogen ions, it is called acidic If a solution has too few hydrogen ions, it is called basic acidic neutral basic Slide 8: A substance that releases hydrogen ions when it is put into a solution is called an acid Cl- H+ Cl- H+ Cl- H+ Cl- H+ Cl- H+ Slide 9: A substance that removes hydrogen ions when it is put into a solution is called an base H+ H+ H+ H+ H+ H+ H+ OH- Na+ OH- Na+ OH- Na+ OH- Na+ H2O H2O H2O H2O Slide 10: The concentration of hydrogen ions [H+] is important to normal function of our cellular proteins Trouble is, the [H+] of most biological solutions is very low For example, pure water has a [H+] of .0000001 moles/liter, or, in scientific notation, 1 x 10-7 M No one, not even scientists, like to work with numbers this small Slide 11: So, the pH scale was developed to make it easier to keep track of those pesky H+ pH is the negative logarithm of [H+] Sounds complicated… but it simply means that you state the hydrogen ion concentration in scientific notation, take the exponent, and change its sign Thus water, rather than being [H+] 1 x 10-7, is simply pH 7 Slide 12: Let’s practice… 1. Lemon juice has a [H+] of 1 x 10-3 M What is the pH of lemon juice? 2. Household bleach has a pH of 13 What is the [H+] of household bleach? 3. Stomach acid has a [H+] of .01 M What is the pH of stomach acid? pH = 3 1 x 10-13 M = .0000000000001 M .01 M = 1 x 10-2 M pH = 2 Slide 13: Because scientific notation is in base ten, a change in one of the pH represents a ten-fold change in [H+] Because pH is the negative logarithm, an increase in pH represents a decrease in [H+] .000001 = 1 x 10-6 pH 6 .0000001 = 1 x 10-7 pH 7 .00000001 = 1 x 10-8 pH 8 Acids, Bases, and pH : Acids, Bases, and pH In summary, we use the pH scale to describe the [H+] of a solution by taking the negative logarithm of the actual [H+] pH 7 is arbitrarily described as neutral Solutions with pH below 7 have a higher [H+] and are therefore acidic Solutions with pH above 7 have a lower [H+] and are therefore basic The pH Scale : The pH Scale