Acids & Bases

Chapter 10.2

Chapter 10Chemical Compounds

• Ionic Compounds Formed by

oppositely charged ions

Metal and nonmetal Properties

Brittle Form crystal lattice High melting point Many dissolve easily

in water and can conduct electricity

• Covalent Compounds Formed by sharing

electrons between atoms

Nonmetals only Properties

Most do not dissolve in water and will not conduct electricity

Low melting points Weaker bonds than

ionic

What is an Acid?

• Acid: Any compound that increases the number of hydronium ions (H+) when dissolved in water.

• Acid solutions usually taste sour.

Lemons & Limes – Citric Acid

Vinegar – Acetic Acid

Sour Candy – Citric Acid

Properties of Acids

1. Produced Hydrogen Ions (H+)

• When added to water, acids dissolve and produce H+ ions.

• Each H + attaches to a water molecule forming a Hydronium ion (H3O+)

2. Conduct Electricity

3. Corrosive

• Destroy body tissue, clothing, or even metal.

• May be poisonous.

4. Taste Sour

5. Changes Indicators to Red, Pink, or Yellow

Uses of Acid

• Sulfuric Acid: (H2SO4) Used in making paper, metals, paint, fertilizers, and car batteries.

• Nitric Acid: (HNO3) Used to make fertilizers, rubber, and plastic.

• Hydrochloric Acid: (HCl) Used to digest food in the stomach, used to kill algae in swimming pools.

• Citric Acid: (C6H7O6) Sour taste in citrus fruits (oranges, lemons, and limes.)

• Ascorbic Acid: (C6H8O6) Vitamin C.

• Carbonic Acid: (H2CO3) Used in carbonated beverages (soda).

What is a Base?

• Base: Any compound that increases the number of hydroxide ions (OH-) when dissolved in water.

• Base solutions usually taste bitter

• Base solutions usually feel slippery (soap solutions).

Properties of Bases

1. Produces Hydroxide Ions (OH-)

• When added to water, bases dissolve and produce OH- ions.

2. Conduct Electricity

3. Corrosive

4. Taste Bitter

5. Feel slippery

6. Change Indicators to Blue

H O

Uses of Bases

• Sodium Hydroxide (NaOH): Used to make paper and soap

• Calcium Hydroxide (Ca(OH)2) : Used in cement, mortar, and plaster.

• Ammonia (NH3): Used in household cleaners and to

make fertilizers.

• Magnesium Hydroxide Mg(OH)2: Used in antacids.

Strong vs. Weak

ACIDS

• Strong Acids: All of the molecules break apart to produce hydrogen ions (H+).

Ex: Sulfuric Acid, Nitric Acid, Hydrochloric Acid

• Weak Acids: Only a few of the molecules break apart to produce hydrogen ions.

Ex: Acetic Acid (vinegar), Citric Acid, and Carbonic Acid.

BASES

• Strong Bases: All of the molecules break apart to produce hydroxide ions (OH-). Ex: Sodium Hydroxide,

Calcium Hydroxide,

• Weak Bases: Only a few of the molecules break apart to produce hydroxide ions (OH-). Ex: Ammonia, Magnesium

Hydroxide.

The pH Scale

• Used to measure how strong an acid or base is.

• Scale ranges from 0-14

• Acids: pH less than 7.

• Bases: pH greater than 7.

• Neutral: pH = 7

0 7 14

ACID BASE

Strong Acid Strong Base

The pH Scale

Indicators

• Chemicals which change colors in the presence of an acid or a base.

• Used to measure the strength of an acid or base.

• Red Cabbage Juice• Litmus Paper• pH Paper

Hydrangea’s will change color based on the acidity of the soil

Neutralization

• Neutralization: When an acid and a base are mixed together.

• Double replacement reaction

• Water and a “salt” are produced.

• Salt: a ionic compound.

BASE ACID SALT WATER

Salts

• Can be produced in three ways.

1. Neutralization

2. Metal & an Acid

3. Metal & a Nonmetal