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General Properties

ACID BASE

Acid (Latin) acidus
Sour
H⁺ makes acid taste sour

Bases – alkaline
Bitter

OH^- generally makes them taste bitter

Slippery because they react with the fats in your skin.

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Acids and Bases

Acids produce hydrogen ions: H⁺
corrosive to metals (H⁺ can attract and take electrons from metals)
erode rocks (acid rain)
Turns litmus to red
pH 1 (strong)- pH6 (weak)

Bases produce hydroxide ions: OH^-
Break down fats and proteins
Corrosive: can dissolve organic matter (skin)
Turns litmus to blue
pH8 (weak) - pH 14 (strong)

Aqueous Solution (aq): dissolved in water. Example: NaOH(aq)

ACID BASE

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ACID or a BASE? Indicators

Indicators – molecular substances that change color when they come into contact with acids and bases (chemical reaction!!)
Indicators we will use: pH paper (red - orange - green - blue) and universal indicator (solutions changes color)

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ACID or a BASE? Indicators

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Review:

What range of numbers does the pH scale cover?

What are the pH numbers for acids and bases?

1-14

1-6 Acid

7 Neutral

8-14 Basic/Alkeline

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Strong and Weak Acids

Strong acids - completely dissociate H⁺ from molecule

Acid: Dissociated Acid:

HCL (aq) --> H⁺ + Cl^-(aq) see gave us H ions
HCH3COO --> CH3OO- + H⁺
Good conductors of electricity.

Weak acids - partially dissociate H+ from molecule. Examples: formic acid, HCOOH; acetic acid, CH₃COOH; and phosphoric acid H₃PO₄

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Strong and Weak Bases

Strong bases - completely dissociate OH^- from molecule

Base: Dissociated Base:

NaOH (aq) --> Na⁺ (aq) + OH^- (aq) see gave us OH ions
HKO (aq) --> K⁺+ OH^- (aq)

Weak bases - partially dissociate OH^-from molecule. Example: ammonia NH₃

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pH and H⁺ Relationship

pH = -log[H+]
Each time the H+ concentration changes by a factor of 10, the pH number changes by 1 unit.

Molarity	[H+]	pH
1.0M HCl	1.0 x 10⁰	0
0.1M HCl	1.0 x 10^-1	1
0.01M HCl	1.0 x 10^-2	2
0.001M HCl	1.0 x 10^-3	3
0.0001M HCl	1.0 x 10^-4	4
0.00001M HCl	1.0 x 10^-5	5

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pH and OH^- Relationship

[H+][OH^-] = 1.0 x 10^-14
The above formula is for any aqueous solution.

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pH and OH- Relationship

Molarity	[OH^-]	[H⁺]	pH
water	1.0 x 10^-7	1.0 x 10^-7	7
0.00001M NaOH	1.0 x 10^-5	1.0 x 10^-9	9
0.0001M NaOH	1.0 x 10^-4	1.0 x 10^-10	10
0.001M NaOH	1.0 x 10^-3	1.0 x 10^-11	11
0.01M NaOH	1.0 x 10^-2	1.0 x 10^-12	12
0.1M NaOH	1.0 x 10^-1	1.0 x 10^-13	13
1.0M NaOH	1.0 x 10⁰	1.0 x 10^-14	14

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Acid Base Theories

Arrhenius Theory of Acids and Bases
Swedish chemist – Svante Arrhenius
Acid is a substance that adds H⁺, to an aqueous solution.
Base is a substance that adds OH^- to an aqueous solution.
Aqueous = dissolved in water

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Acid Base Theories - Bronsted-Lowry

Danish chemist - Johannes Bronsted

English chemist - Thomas Lowry

Explains how bases w/o an OH- ion behave.
Acid is a substance that can donate a proton to another substance.
Base is a substance that can accept a proton from another substance.

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