The word “ion” just mean it has a charge (+/-) Chapter 9: Chemical Names and Formulas 9.1 Naming Ions -Monoatomic Ions -1 atom -Cations (+) and Anions (-) -Example: Na+ is the sodium ion -Polyatomic Ions -More than one atom -Common names, back of periodic table -Example: CN- is cyanide The word “ion” just mean it has a charge (+/-)

Chapter 9: Chemical Names and Formulas 9.2 Naming and Writing Formulas for Ionic Compounds -Binary Compound -Composed of 2 elements (ex: NaCl) -We already learned this… 1. Write the name of the 1st element 2. Write the name of the 2nd element, change ending to –ide 3. If it’s a transition metal, use roman numerals 4. Example: CaF2 is calcium fluoride

Chapter 9: Chemical Names and Formulas 9.2 Naming and Writing Formulas for Ionic Compounds -Writing Formulas -Overall charge must be zero -How many atoms of each element are necessary to make a neutral charge? K+ Cl- Fe3+ O2- Ca2+ S2-

Chapter 9: Chemical Names and Formulas 9.2 Naming and Writing Formulas for Ionic Compounds -Writing Formulas for COMPOUNDS -Overall charge must be zero Ca+2 (NO3)- Li1+ (CO3)2- Mg2+ (OH)-2

Chapter 9: Chemical Names and Formulas 9.3 Naming and Writing Formulas for Molecular Compounds -We already did this… 1. Write 1st name of first element. 2. Write 2nd name of second element. Change ending to –ide 3. Use prefixes (mono – 1, di – 2, etc…) 4. Example: H2O is dihydrogen monoxide

Chapter 9: Chemical Names and Formulas 9.4 Naming and Writing Formulas for Acids and Bases -Acids are ionic compounds with unique properties -Acid = contains one or more hydrogen atoms and produces hydrogen ions (H+) when dissolved in water.

Chapter 9: Chemical Names and Formulas 9.4 Naming and Writing Formulas for Acids and Bases -Acids have the chemical formula HnX where X is a monatomic ion or polyatomic anion, and n is the number of hydrogen ions that are combined with the anion. -Example: HCN is H+ and CN- Acids always have an H

Chapter 9: Chemical Names and Formulas 9.4 Naming and Writing Formulas for Acids and Bases 1. When the name of (X) ends in –ide, the prefix is hydro- The stem of the anion has the suffix –ic and is followed by the word acid. -HCl is hydrochloric acid 2. When the anion name ends in –ite, the acid name is the stem of the anion with the suffix -ous, followed by the word acid. - H2SO3 is sulfurous acid

Chapter 9: Chemical Names and Formulas 9.4 Naming and Writing Formulas for Acids and Bases 3. When the anion name ends in –ate, the acid name is the stem of the anion with the suffix –ic followed by the word acid. -HNO3 is nitric acid

Chapter 9: Chemical Names and Formulas 9.4 Naming and Writing Formulas for Acids and Bases -Base = produces hydroxide (OH-) ions in water 1. Naming bases is the same as an ionic compound -NaOH is sodium hydroxide Most bases have an OH or are known to have a negative charge (aka they want an H+)

Chapter 9: Chemical Names and Formulas 9.5 The Laws Governing Formulas and Name -The law of definite proportions: the ratio of atoms can be expressed as a ratio of masses. -Elements always combine in simple whole-number ratios -Their proportions by mass must always be the same

Chapter 9: Chemical Names and Formulas 9.5 The Laws Governing Formulas and Name -The law of definite proportions: the ratio of atoms can be expressed as a ratio of masses.

Chapter 9: Chemical Names and Formulas 9.5 The Laws Governing Formulas and Name -The law of multiple proportions: You can reduce the ratio’s 16g O (in H202 sample that has 1 g H) = 16 = 2 = 2:1 8g O (in H20 sample that has 1 g H) = 8 = 1