# Authority makes some people grow — and others just swell.

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Authority makes some 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 Bases Lesson 3

Problem Find the [OH - ] if the [ H + ] = 1.2 x 10 -3 M K w = [H + ] x [OH - ] 1 x 10 -14 (mol / L) 2 = [OH - ] x 1.2 x 10 -3 M Answer: [OH - ] = 8.33 x 10 -12 M Find the [OH - ] if the [ H + ] = 1.2 x 10 -3 M K w = [H + ] x [OH - ] 1 x 10 -14 (mol / L) 2 = [OH - ] x 1.2 x 10 -3 M Answer: [OH - ] = 8.33 x 10 -12 M

Problem 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 M 2 = 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 M 2 = 1.34 x 10 -10 M x [H + ]

Work [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

Neutralize acids with a base 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

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

Stomach Acid - HCl Neutralized

Indicator A weak acid or base that undergoes dissociation in a known pH range. Ex: Phenolphthalein Thymol blue Litmus paper A weak acid or base that undergoes dissociation in a known pH range. Ex: Phenolphthalein Thymol blue Litmus paper

Litmus Test and Other Color Changes Acids and bases cause certain colored dyes to change color. The most common of these dyes is litmus.

Litmus 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 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 HNO 3 NH 3 is oxidized on Pt surface in air to NO and NO 2. NO 2 in water gives HNO 3.

HNO 3, HCl, H 2 SO 4 and HClO 4 are among the only known strong acids. Strong and Weak Acids/Bases

Weak acid Ionizes only slightly in aqueous solution. Ex: Boric Acid - H 3 BO 3, Chloric Acid - HClO, Hydrosulfuric acid - H 2 S Ionizes only slightly in aqueous solution. Ex: Boric Acid - H 3 BO 3, Chloric Acid - HClO, Hydrosulfuric acid - H 2 S

Strong/Weak Acids

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: 100% dissociated in water.Strong Base: 100% dissociated in water. NaOH(aq) ---> Na + (aq) + OH - (aq) NaOH(aq) ---> Na + (aq) + OH - (aq) Strong Base: 100% dissociated in water.Strong Base: 100% dissociated in water. NaOH(aq) ---> Na + (aq) + OH - (aq) NaOH(aq) ---> Na + (aq) + OH - (aq) Strong and Weak Acids/Bases Other common strong bases include KOH and Ca(OH) 2. CaO (lime) + H 2 O --> Ca(OH) 2 (slaked lime) Ca(OH) 2 (slaked lime) CaO

Weak base Do not dissociate completely in an aqueous solution. Ex: Sodium cyanide- NaCN Ammonia - NH 3 Methal amide - CH 3 NH 2 Do not dissociate completely in an aqueous solution. Ex: Sodium cyanide- NaCN Ammonia - NH 3 Methal amide - CH 3 NH 2

Fig. 17-3, p.809

Fig. 17-1, p.798

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 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 Nonmetal oxides form acids when they react with water.

Basic anhydrides Metal oxides, on the other hand, react with water to form bases. Ex: Metal when it burns leaves an ash. Metal oxides, on the other hand, react with water to form bases. Ex: Metal when it burns leaves an ash.

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