Acids & Bases Chapter 10.2

Chapter 10 Chemical 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 (H 3 O + ) 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: (H 2 SO 4) Used in making paper, metals, paint, fertilizers, and car batteries. Nitric Acid: (HNO 3 ) 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: (C 6 H 7 O 6 ) Sour taste in citrus fruits (oranges, lemons, and limes.) Ascorbic Acid: (C 6 H 8 O 6 ) Vitamin C. Carbonic Acid: (H 2 CO 3 ) 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 (NH 3 ):  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 = ACIDBASE 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. BASEACIDSALTWATER

Salts Can be produced in three ways. 1.Neutralization 2.Metal & an Acid 3.Metal & a Nonmetal