pH of Strong BasesPART III

In order for you to obtain the pH of strongbases, you must be able to recognize astrong base.

In order for you to obtain the pH of strongbases, you must be able to recognize astrong base.

If you do not know how to recognize an baseor if you do not know which ones are strong,this slide show may be useless to you.

Go back and learn the difference betweenstrong soluble bases, insoluble (slightlysoluble) bases and weak soluble bases!

In order for you to obtain the pH of strongbases, you must be able to recognize astrong base.

If you do not know how to recognize an baseor if you do not know which ones are strong,this slide show may be useless to you.

Go back and learn the difference betweenstrong soluble bases, insoluble (slightlysoluble) bases and weak soluble bases!

A review of Brnsted-Lowry acid-baseconcepts would also be helpful.

pH of Strong Bases

The strong soluble bases are either from the group I metalhydroxides or the group II metal hydroxides. These are solidswhen not dissolved in water and completely ionize* whendissolved in water.

pH of Strong Bases

The strong soluble bases are either from the group I metalhydroxides or the group II metal hydroxides. These are solidswhen not dissolved in water and completely ionize* whendissolved in water.

Group I: MOH ! M+ + OH!

Group II: M(OH)2 ! M2+ + 2OH!

pH of Strong Bases

The strong soluble bases are either from the group I metalhydroxides or the group II metal hydroxides. These are solidswhen not dissolved in water and completely ionize* whendissolved in water.

Group I: MOH ! M+ + OH!

Group II: M(OH)2 ! M2+ + 2OH!

Thus for group I, the molarity of the OH! ion is the same asthat calculated for the formal concentration of the hydroxide.

pH of Strong Bases

The strong soluble bases are either from the group I metalhydroxides or the group II metal hydroxides. These are solidswhen not dissolved in water and completely ionize* whendissolved in water.

Group I: MOH ! M+ + OH!

Group II: M(OH)2 ! M2+ + 2OH!

Thus for group I, the molarity of the OH! ion is the same asthat calculated for the formal concentration of the hydroxide.

Group I: [OH!] = CM(MOH)

pH of Strong BasespH of Strong Bases

The strong soluble bases are either from the group I metalhydroxides or the group II metal hydroxides. These are solidswhen not dissolved in water and completely ionize* whendissolved in water.

Group I: MOH ! M+ + OH!

Group II: M(OH)2 ! M2+ + 2OH!

Thus for group I, the molarity of the OH! ion is the same asthat calculated for the formal concentration of the hydroxide.

Group I: [OH!] = CM(MOH)For group II, the molarity of the OH! ion is twice that of theformal concentration of the hydroxide.

pH of Strong BasespH of Strong Bases

The strong soluble bases are either from the group I metalhydroxides or the group II metal hydroxides. These are solidswhen not dissolved in water and completely ionize* whendissolved in water.

Group I: MOH ! M+ + OH!

Group II: M(OH)2 ! M2+ + 2OH!

Thus for group I, the molarity of the OH! ion is the same asthat calculated for the formal concentration of the hydroxide.

Group I: [OH!] = CM(MOH)For group II, the molarity of the OH! ion is twice that of theformal concentration of the hydroxide.

Group II: [OH!] = 2CM(M(OH)2)

Example 1: What is the pH for a solution of 0.015 M NaOH?

pH of Strong Bases

Example 1: What is the pH for a solution of 0.015 M NaOH?

This is a group I metal hydroxide, therefore:

pH of Strong Bases

Example 1: What is the pH for a solution of 0.015 M NaOH?

This is a group I metal hydroxide, therefore:

[OH!] = CM(MOH)

pH of Strong Bases

Example 1: What is the pH for a solution of 0.015 M NaOH?

This is a group I metal hydroxide, therefore:

[OH!] = CM(MOH)

[OH!] = 0.015

pH of Strong Bases

Example 1: What is the pH for a solution of 0.015 M NaOH?

This is a group I metal hydroxide, therefore:

[OH!] = CM(MOH)

[OH!] = 0.015

pOH = !log(0.015)

pH of Strong Bases

Example 1: What is the pH for a solution of 0.015 M NaOH?

This is a group I metal hydroxide, therefore:

[OH!] = CM(MOH)

[OH!] = 0.015

pOH = !log(0.015)

pOH = 1.82

pH of Strong Bases

Example 1: What is the pH for a solution of 0.015 M NaOH?

This is a group I metal hydroxide, therefore:

[OH!] = CM(MOH)

[OH!] = 0.015

pOH = !log(0.015)

pOH = 1.82

But: 14.00 = pH + pOH

pH of Strong Bases

Example 1: What is the pH for a solution of 0.015 M NaOH?

This is a group I metal hydroxide, therefore:

[OH!] = CM(MOH)

[OH!] = 0.015

pOH = !log(0.015)

pOH = 1.82

But: 14.00 = pH + pOH

So: pH = 12.18

pH of Strong Bases

Example 2: What is the pH for a solution of 0.015 MBa(OH)2?

pH of Strong Bases

This is a group II metal hydroxide, therefore:

pH of Strong Bases

Example 2: What is the pH for a solution of 0.015 MBa(OH)2?

[OH!] = 2CM(MOH)

pH of Strong Bases

This is a group II metal hydroxide, therefore:

Example 2: What is the pH for a solution of 0.015 MBa(OH)2?

[OH!] = 2 0.015

pH of Strong Bases

[OH!] = 2CM(MOH)

This is a group II metal hydroxide, therefore:

Example 2: What is the pH for a solution of 0.015 MBa(OH)2?

pOH = !log(0.030)

pH of Strong Bases

[OH!] = 2 0.015

[OH!] = 2CM(MOH)

This is a group II metal hydroxide, therefore:

Example 2: What is the pH for a solution of 0.015 MBa(OH)2?

pOH = 1.52

pH of Strong Bases

pOH = !log(0.030)[OH!] = 2 0.015

[OH!] = 2CM(MOH)

This is a group II metal hydroxide, therefore:

Example 2: What is the pH for a solution of 0.015 MBa(OH)2?

But: 14.00 = pH + pOH

pH of Strong Bases

pOH = 1.52pOH = !log(0.030)[OH!] = 2 0.015

[OH!] = 2CM(MOH)

This is a group II metal hydroxide, therefore:

Example 2: What is the pH for a solution of 0.015 MBa(OH)2?

So: pH = 12.48

pH of Strong Bases

But: 14.00 = pH + pOHpOH = 1.52pOH = !log(0.030)[OH!] = 2 0.015

[OH!] = 2CM(MOH)

This is a group II metal hydroxide, therefore:

Example 2: What is the pH for a solution of 0.015 MBa(OH)2?

pH of Strong BasesPART III

THE END

Go on to the slideshow on weak acids.