Authority makessome people

grow—

and others just swell.

Authority makessome people

grow—

and others just swell.

• This question was asked to pre-schoolers.

• Which way is the school bus traveling?• Answer: Left (There is no door on this

side.

• This question was asked to pre-schoolers.

• Which way is the school bus traveling?• Answer: Left (There is no door on this

side.

Acids and BasesAcids and Bases

Lesson 3Lesson 3

ProblemProblem• Find the [OH -] if the [ H+ ] = 1.2 x 10-3 M

• Kw = [H+] x [OH -]

1 x 10 -14 (mol / L)2 = [OH -] x 1.2 x 10-3 MAnswer:• [OH - ] = 8.33 x 10-12 M

• Find the [OH -] if the [ H+ ] = 1.2 x 10-3 M

• Kw = [H+] x [OH -]

1 x 10 -14 (mol / L)2 = [OH -] x 1.2 x 10-3 MAnswer:• [OH - ] = 8.33 x 10-12 M

ProblemProblem

• Find the pH if the• [OH -] = 1.34 x 10-10 M. • Identify is this a base or acid?

• First solve to find the [H+ ] • 1 x 10 -14 M2 = 1.34 x 10 -10 M x [H+ ]

• Find the pH if the• [OH -] = 1.34 x 10-10 M. • Identify is this a base or acid?

• First solve to find the [H+ ] • 1 x 10 -14 M2 = 1.34 x 10 -10 M x [H+ ]

WorkWork

• [H+ ] = 7.46 x 10-5 M

• Now take the - log of this value.

• - log 7.46 x 10-5 M• Answer:• pH = 4.127 this is an acid

• [H+ ] = 7.46 x 10-5 M

• Now take the - log of this value.

• - log 7.46 x 10-5 M• Answer:• pH = 4.127 this is an acid

Acid + base -----> salt + water

Acid + base -----> salt + water

Neutralize acids with a base

Neutralize acids with a base

• Of about the same pH, otherwise will requires an adjustment by volumes.

• Of about the same pH, otherwise will requires an adjustment by volumes.

p.816a

Sodium Bicarbonate + Acetic Acid

Sodium Acetate + water + carbon dioxide

Fig. 17-4, p.816

Neutralizes stomach Acid, therefore must be a _________________Base

AntacidsAntacids

• Bases that are use to help neutralize the acids in our stomachs.

• Bases that are use to help neutralize the acids in our stomachs.

Stomach Acid - HClNeutralized

Stomach Acid - HClNeutralized

Indicator Indicator

• A weak acid or base that undergoes dissociation in a known pH range.

Ex: Phenolphthalein Thymol blueLitmus paper

• A weak acid or base that undergoes dissociation in a known pH range.

Ex: Phenolphthalein Thymol blueLitmus paper

Litmus Test and Other Color Changes

Litmus Test and Other Color Changes

• Acids and bases cause certain colored dyes to change color. The most common of these dyes is litmus.

• Acids and bases cause certain colored dyes to change color. The most common of these dyes is litmus.

LitmusLitmus

• When added to a base, litmus is blue.

• When mixed with an acid, litmus is red.

• When added to a base, litmus is blue.

• When mixed with an acid, litmus is red.

Strong acid Strong acid

• Completely ionized in an aqueous solution.

• Ex: Sulfuric acid, hydrochloric acid, and nitric acid.

• Completely ionized in an aqueous solution.

• Ex: Sulfuric acid, hydrochloric acid, and nitric acid.

Commercial Prep of Commercial Prep of HNOHNO33

Commercial Prep of Commercial Prep of HNOHNO33

NHNH33 is oxidized on Pt surface in air is oxidized on Pt surface in air to NO and NOto NO and NO22. NO. NO22 in water gives in water gives HNOHNO33..

NHNH33 is oxidized on Pt surface in air is oxidized on Pt surface in air to NO and NOto NO and NO22. NO. NO22 in water gives in water gives HNOHNO33..

HNO3, HCl, H2SO4 and HClO4 are among the only known strong acids.

Strong and Weak Strong and Weak Acids/BasesAcids/Bases

Weak acid Weak acid

• Ionizes only slightly in aqueous solution.

• Ex:

• Boric Acid - H3BO3,

• Chloric Acid - HClO,

• Hydrosulfuric acid - H2S

• Ionizes only slightly in aqueous solution.

• Ex:

• Boric Acid - H3BO3,

• Chloric Acid - HClO,

• Hydrosulfuric acid - H2S

Strong/Weak AcidsStrong/Weak Acids

Strong base Strong base

• Dissociate completely into metal ions and hydroxide ions in aqueous solution.

• Ex: • Sodium hydroxide, • Potassium hydroxide, • Calcium hydroxide

• Dissociate completely into metal ions and hydroxide ions in aqueous solution.

• Ex: • Sodium hydroxide, • Potassium hydroxide, • Calcium hydroxide

•Strong Base:Strong Base: 100% dissociated 100% dissociated in water.in water.

NaOH(aq) ---> NaNaOH(aq) ---> Na++(aq) + OH(aq) + OH--(aq)(aq)

Strong and Weak Acids/BasesStrong and Weak Acids/Bases

Other common strong Other common strong bases include KOH and bases include KOH and Ca(OH)Ca(OH)22..

CaO (lime) + HCaO (lime) + H22O -->O -->

Ca(OH)Ca(OH)22 (slaked lime) (slaked lime)CaOCaO

Weak base Weak base

• Do not dissociate completely in an aqueous solution.

• Ex: • Sodium cyanide- NaCN

• Ammonia - NH3

• Methal amide - CH3NH2

• Do not dissociate completely in an aqueous solution.

• Ex: • Sodium cyanide- NaCN

• Ammonia - NH3

• Methal amide - CH3NH2

Fig. 17-3, p.809

Fig. 17-1, p.798

Amphotoeric Amphotoeric

• Substance that can act as either an acid or a base.

• Ex: water

• Substance that can act as either an acid or a base.

• Ex: water

Electrolytes Electrolytes

• Can be either an acid or a base.

• A substance that dissociates into ions in solution, thereby becoming an electrical conductor.

• Can be either an acid or a base.

• A substance that dissociates into ions in solution, thereby becoming an electrical conductor.

Acidic anhydrides Electrolytes

Acidic anhydrides Electrolytes

• Nonmetal oxides form acids when they react with water.

• Nonmetal oxides form acids when they react with water.

Basic anhydrides Basic anhydrides

• Metal oxides, on the other hand, react with water to form bases.

Ex: Metal whenit burns leavesan ash.

• Metal oxides, on the other hand, react with water to form bases.

Ex: Metal whenit burns leavesan ash.