Name the following compounds: Warm Up Name the following compounds: Answer: Cl2O7 K2CrO4 N2H4 SiCl4 MnPO4 Dichlorine heptoxide Potassium chromate Dinitrogen tetrahydride Silicon tetrachloride Manganese (III) phosphate

Naming Acids Acids are a group of ionic compounds with unique properties. An acid is a compound that contains one or more hydrogen atoms and produces hydrogen ions (H+) when dissolved in water. Chemical formula of an acid: HnX X = monatomic anion or polyatomic anion n = number of hydrogen atoms

How to name an acid… Depends on the name of the ANION 1. When the name of the anion (X) ends in –ide A. The acid name begins with the prefix hydro- B. The stem of the anion has a suffix –ic followed by the word acid Example: HCl – (X = chloride) hydrochloric acid 2. When the name of the anion (X) ends in –ite A. The stem of the anion has a suffix –ous, followed by the word acid Example: H2SO3 – (X = sulfite) sulfurous acid 3. When the name of the anion (X) ends in –ate A. The stem of the anion has a suffix –ic, followed by the word acid Example: H3PO4 – (X = phosphate) phosphoric acid

Naming Common Acids Textbook Table 9.5 Anion Ending Example Acid Name -ide Chloride, Cl- Hydro-(stem)-ic acid Hydrochloric acid -ite Sulfite, SO32- (stem)-ous acid Sulfurous acid -ate Phospate, PO43- (stem)-ic acid Phosphoric acid

Practice: H2S HNO2 H2CO3 HC2H3O2 HF H2O Hydrosulfuric acid X = sulfide Hydrosulfuric acid Nitrous acid X = nitrite Carbonic acid X = carbonate Acetic acid X = acetate Hydrofluoric acid X = fluoride Water is NOT an Acid pH = 7 Dihydrogen monoxide X = oxide

Naming Bases A base is an ionic compound that produces hydroxide ions when dissolved in water. Bases are named in the same way as other ionic compounds The name of the cation, followed by the name of the anion Anion will always be hydroxide (OH1-) Exception: NH3 - ammonia

Practice: LiOH Al(OH)3 Fe(OH)3 Mg(OH)2 Pb(OH)2 HOH Lithium hydroxide Aluminum hydroxide Iron (III) hydroxide Magnesium hydroxide Lead (II) hydroxide Water is NOT a Base pH = 7 Dihydrogen monoxide

Laws Governing Formulas & Names The Law of Definite Proportions In samples of any chemical compound, the masses of the elements are always in the same proportion The Law of Multiple Proportions Whenever the same two elements form more than one compound, the different masses of one element that combine with the same mass of the other element are in the ratio of small whole numbers

Compound contains a polyatomic ion Naming a Compound: QxRy Q=H? Acid: Look at ending of anion YES ≥ 2 elements? NO Q=Metal? NO Compound is binary Ends in –ide Q=Group A? YES Compound contains a polyatomic ion Ends in –ite or -ate NO Ionic: Use a roman numeral YES Ionic: Name the ions NO Covalent: Use prefixes Q=Group A? YES YES Ionic: Name the ions Ionic: Use a roman numeral NO

Writing a Formula: Name of Compound Contains prefixes? Covalent Compound YES Use prefixes to write formula. Never reduce! Ionic Compound NO Roman Numerals Polyatomic Ions Group A Elements Determine charges to write formula Use Periodic Table Charge for Cation Reference Table Balance Charges Use criss-cross method. Reduce if necessary. Add parentheses for multiple polyatomic ions.