Upload
madeleine-applebee
View
215
Download
1
Tags:
Embed Size (px)
Citation preview
© Copyright Pearson Prentice Hall
Slide 2 of 50
Hydrogen Ions and Acidity
To test a diagnosis of diabetic coma, a doctor orders several tests, including the acidity of the patient’s blood. Results from this test will be expressed in units of pH. You will learn how the pH scale is used to indicate the acidity of a solution and why the pH scale is used.
19.2
Slide 3 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity Hydrogen Ions from Water
Hydrogen Ions from Water
The reaction in which water molecules produce ions is called the self-ionization of water.
19.2
Slide 4 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity Hydrogen Ions from Water
In the self-ionization of water, a proton (hydrogen ion) transfers from one water molecule to another water molecule.
19.2
© Copyright Pearson Prentice Hall
Hydrogen Ions and Acidity >
Slide 5 of 50
Ion Product Constant for Water
Ion Product Constant for Water
How are [H+] and [OH-] related in an aqueous solution?
19.2
Slide 6 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity Ion Product Constant for Water
For aqueous solutions, the product of the hydrogen-ion concentration and the hydroxide-ion concentration equals 1.0 10-14.
Any aqueous solution in which [H+] and [OH-] are equal is described as a neutral solution.
19.2
Slide 7 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity Ion Product Constant for Water
The product of the concentrations of the hydrogen ions and hydroxide ions in water is called the ion-product constant for water (Kw).
19.2
Slide 8 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity Ion Product Constant for Water
An acidic solution is one in which [H+] is greater than [OH-].
19.2
Slide 9 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity Ion Product Constant for Water
Unrefined hydrochloric acid, commonly called muriatic acid, is used to clean stone buildings and swimming pools.
19.2
Slide 10 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity Ion Product Constant for Water
A basic solution is one in which [H+] is less than [OH]. Basic solutions are also known as alkaline solutions.
19.2
Slide 11 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity Ion Product Constant for Water
Sodium hydroxide, or lye, is commonly used as a drain cleaner.
19.2
© Copyright Pearson Prentice Hall
Slide 16 of 50
Practice Problems for Sample Problem 19.1
Problem Solving 19.10
Solve Problem 10 with the help of an interactive guided tutorial.
© Copyright Pearson Prentice Hall
Hydrogen Ions and Acidity >
Slide 17 of 50
The pH Concept
The pH Concept
How is the hydrogen-ion concentration used to classify a solution as neutral, acidic, or basic?
19.2
Slide 18 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity The pH Concept
The pH of a solution is the negative logarithm of the hydrogen-ion concentration.
19.2
Slide 19 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity The pH Concept
Calculating pH
19.2
Slide 20 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity The pH Concept
A solution in which [H+] is greater than 1 10–7 M has a pH less than 7.0 and is acidic. The pH of pure water or a neutral aqueous solution is 7.0. A solution with a pH greater than 7 is basic and has a [H+] of less than 1 10–7 M.
19.2
Slide 23 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity The pH Concept
Calculating pOH
19.2
Slide 24 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity The pH Concept
pH and Significant Figures
19.2
© Copyright Pearson Prentice Hall
Slide 29 of 50
Practice Problems for Sample Problem 19.2
Problem Solving 19.12
Solve Problem 12 with the help of an interactive guided tutorial.
© Copyright Pearson Prentice Hall
Slide 34 of 50
Practice Problems for Sample Problem 19.3
Problem Solving 19.14
Solve Problem 14 with the help of an interactive guided tutorial.
© Copyright Pearson Prentice Hall
Hydrogen Ions and Acidity >
Slide 35 of 50
Measuring pH
Measuring pH
What is the most important characteristic of an acid-base indicator?
19.2
© Copyright Pearson Prentice Hall
Hydrogen Ions and Acidity >
Slide 36 of 50
Measuring pH
An indicator is a valuable tool for measuring pH because its acid form and base form have different colors in solution.
19.2
Slide 37 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity Measuring pH
Phenolphthalein changes from colorless to pink at pH 7–9.
19.2
© Copyright Pearson Prentice Hall
Slide 42 of 50
Practice Problems for Sample Problem 19.4
Problem Solving 19.15
Solve Problem 15 with the help of an interactive guided tutorial.
Slide 43 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity Measuring pH
Acid-Base Indicators
19.2
Slide 45 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity Measuring pH
Universal Indicators
19.2
Slide 46 of 50
© Copyright Pearson Prentice Hall
>Hydrogen Ions and Acidity Measuring pH
pH Meters
19.2
© Copyright Pearson Prentice Hall
Slide 47 of 50
Section Quiz
-or-Continue to: Launch:
Assess students’ understanding of the concepts in Section
19.2 Section Quiz.
19.2.
© Copyright Pearson Prentice Hall
Slide 48 of 50
19.2 Section Quiz.
1. If the [OH-] in a solution is 7.65 10-3M, what is the [H+] of this solution?
a. 7.65 10-17M
b. 1.31 10-12M
c. 2.12M
d. 11.88M
© Copyright Pearson Prentice Hall
Slide 49 of 50
19.2 Section Quiz.
2. The [OH-] for four solutions is given below. Which one of the solution is basic?
a. 1.0 x 10-6M
b. 1.0 x 10-8M
c. 1.0 x 10-7M
d. 1.0 x 10-14M
© Copyright Pearson Prentice Hall
Slide 50 of 50
3. What is the pH of a solution with a hydrogen-ion concentration of 8.5 x 10-2M?
a. 12.93
b. 8.50
c. 5.50
d. 1.07
19.2 Section Quiz.