Chemical Compounds Chapter 10 State Standards: 3.b; 3.c; 5.e; 7.c 1 Contreras

10-1: Ionic and Covalent Compounds Contreras 2

Ionic Compounds Attraction between oppositely charged ions ▫(+ and -) ▫Have ionic bonds Mostly metals and nonmetals ▫Metal atoms become positively charged when electrons are transferred to nonmetals ▫NaCl 3 Contreras (Na loses electrons, Cl gains electrons)

Ionic Compound Properties Brittleness ▫Crystal lattice arrangement High melting point ▫Because of strong bonds between ions Highly soluble (dissolve easily) in water Conducts electricity Contreras 4

Covalent Compounds Atoms are bound by shared valence electrons Bonding of two nonmetals Molecules are made up of covalent compounds Contreras 5

Covalent Compound Properties Most not very soluble (do not dissolve well in water) Low melting point ▫Weaker bonds are easier to break Most do not conduct electricity because they do not form ions when dissolved in water Contreras 6

Types of Compounds IonicCovalent Between positive and negative ions Atoms share valence electrons Metal and nonmetalNonmetal and nonmetal Brittle (crystal lattice structure) Make molecules SolubleNot very soluble High melting pointLow melting point Conduct electricityDo not conduct electricity Ex. SaltEx. H 2 O Contreras 7

10-2: Acids and Bases Contreras 8

Acids Have hydronium ions (H 3 O + ) ▫H 2 O + H +  H 3 O + Uses ▫Hydrochloric acid used in separating metals from their ores, pool maintenance against algae, stomach digestion Contreras 9

Acid Properties Sour Taste ▫Corrosive – ability to destroy many things Change colors of indicators ▫Litmus paper – changes to red React with metals to form hydrogen gas Conducts electric current ▫When acids are dissolved in water, they break apart and form ion Contreras 10

Bases Have hydroxide ions (OH-) ▫Hydroxide ion is an oxygen bonded to a hydrogen with a negative charge Uses ▫Sodium hydroxide is used in soap, paper, oven cleaners and drain decloggers ▫Ammonia – household cleaners and fertilizers Contreras 11

Base Properties Bitter taste and slippery feel ▫Corrosive ▫Ex. Soap Change color of indicators ▫Litmus paper – changes to blue Conduct electrical current ▫Hydroxide ions have a negative charge Contreras 12

Contreras 13 Neutral Solution (pH of 7) Basic Acidic pH Scale

Acids vs. Bases AcidsBases Hydronium Ions (H3O+) Positive Charge Hydroxide Ions (OH-) Negative Charge Taste SourTaste Bitter Forms Ions in WaterFeels Slippery pH 0-7pH 7-14 Turns Litmus RedTurns Litmus Blue Ex. Battery AcidEx. Cleaning Products Contreras 14

10-3: Solutions of Acids and Bases Contreras 15

Solutions of Acids and Bases The concentration of an acid or base is not the same as its strength Strong vs Weak acid ▫In a strong acid, all of the acid molecules break apart and form Hydrogen ions (H + ) when dissolved in water. In a weak acid, only a few do. Strong vs Weak base ▫In a strong base, all of the base molecules break apart to form Hydroxide ions (OH - ). In a weak base, only a few break apart. Contreras 16

The pH Scale Describes how acidic or basic a solution is Measures the Hydronium ion (H 3 O + ) concentration in a solution Contreras 17

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Salts An ionic compound formed from positive ion of a base and the negative ion of an acid When an acid neutralizes a base, salt and water are produced Contreras 19