Chemical Names and Formulas Chapter 9 Chemical Names and Formulas

You do not want to wait until the last minute to study for this test! Notice You do not want to wait until the last minute to study for this test!

Naming Ions 9.1

Monatomic Ions Monatomic ions consist of a single atom with a positive or negative charge resulting from the loss or gain of one or more valence electrons

How can you determine the charges of monatomic (metal) ions? Cations Metallic elements lose electrons Key Question How can you determine the charges of monatomic (metal) ions? Groups 1A, 2A and 3A metals form cations with positive charges equal to their group number. Name cations by adding ion to the end of the name of the element For example, Calcium as an ion would be referred to as calcium ion, which is Ca2+ , not Ca.

Practice Naming Cations Write the symbol and the name of the ion that will form from the following: Potassium Aluminum Strontium Lithium

How can you determine the charges of monatomic (nonmetal) ions? Anions Nonmetals tend to gain electrons to form anions, the charge of the ion is negative Key Question How can you determine the charges of monatomic (nonmetal) ions? The charge of any ion of a Group A nonmetal is determined by subtracting 8 from the group number The anion names start with the stem of the element name and ends in -ide For example, chlorine as an ion would be referred to as chloride, which is Cl-, not Cl.

Practice Naming Anions Write the symbol and the name of the ion that will form from the following: Fluorine Nitrogen Selenium Phosphorus Bromine

Metals That Form More Than One Ion Many of the transition metals form more than one cation with different ionic charges Key Question How can you determine the charges of monatomic (transition metal) ions? The number of electrons lost We will use the stock system when naming transition metal ions Place the number of electrons inside of parentheses For example, if iron loses 2 electrons it would be referred to as iron (II), not just iron! It’s symbol would be Fe2+.

Practice Naming Transition Metal Ions Write the symbol and the name of the ion that will form from the following: Copper (lose 1 electron) Iron (lose 3 electrons) Lead (lose 4 electrons) Tin (lose 2 electrons) Copper (lose 2 electrons)

Polyatomic Ions Key Question How do polyatomic ions differ from monatomic ions? How are they similar? A polyatomic ion is composed of more than one atom, where as a monatomic ion consists of only one. Both monatomic ions and polyatomic ions behave as a single unit and carries a charge

You will get to use this chart on the test! Polyatomic Ions See Back of Periodic Table You will get to use this chart on the test! Take note of the endings –ite and –ate These endings relate to the amount of oxygen atoms present -ite ending has one less oxygen that the –ate

Naming and Writing Formulas for Ionic Compounds 9.2

Binary Ionic Compounds A binary compound is composed of two elements A binary compound may be ionic or molecular Key Question (1 of 2) How do you determine the formula of a binary compound? First write the symbol of the cation and then the anion. Then add the subscripts as needed to balance the charges.

Practice Writing Formulas for Binary Ionic Compounds Write formulas for compounds formed from these atoms: Model Magnesium ion and nitride Copper (I) ion and sulfide Lithium ion and oxide Calcium ion and oxide IN CLASS ONLY!

Practice Writing Formulas for Binary Ionic Compounds Write formulas for compounds formed from these atoms: Potassium ion and nitride Calcium ion and nitride Aluminum ion and nitride IN CLASS ONLY!

Naming Binary Ionic Compounds Key Question (2 of 2) How do you determine the name of a binary ionic compound? Place the cation name first, followed by the anion name. If the metallic element has more than one common ionic charge, a Roman numeral must be included in the cation name.

Practice Naming Binary Ionic Compounds Name the following binary ionic compounds: Model Ba3N2 BaO BaF2 CuCl2 CuCl IN CLASS ONLY!

Practice Naming Binary Ionic Compounds Name the following binary ionic compounds: AlP Al2O3 AlBr3 Cr3N2 CrN IN CLASS ONLY!

Writing Formulas for compounds With Polyatomic Ions Key Question (1 of 2) How do you determine the formula of a compound with a polyatomic ion? First write the symbol for the cation, followed by the symbol for the anion. Then add subscripts as needed to balance the charges. Whenever more than one polyatomic ion is needed to balance the charges in an ionic compound, use parentheses to set off the polyatomic ion in the formula.

Practice Writing Formulas of Compounds That Contain Polyatomic Ions Write formulas for compounds formed from the following: Model Magnesium ion and nitrate Magnesium ion and nitrite Magnesium ion and hydrogen phosphate Magnesium ion and phosphite IN CLASS ONLY!

Practice Writing Formulas of Compounds That Contain Polyatomic Ions Write formulas for compounds formed from the following: Potassium ion and hydroxide Potassium ion and sulfate Potassium ion and phosphate Potassium ion and permanganate *Ammonium ion and nitride IN CLASS ONLY!

Naming Compounds With Polyatomic Ions Key Question (2 of 2) How do you determine the name of a compound with a polyatomic ion? State the cation name first and then the anion name. If the cation is a metallic element that has more than one common ionic charge, include a Roman numeral in the cation name.

Practice Naming Compounds That Contain Polyatomic Ions Name the following ionic compounds: Model Al(H2PO4)3 Al2(SO3)3 AlPO3 (NH4)2O Cu3(PO4)2 Cu3PO4 IN CLASS ONLY!

Practice Naming Compounds That Contain Polyatomic Ions Name the following ionic compounds: Mn3(PO4)2 MnPO4 Li2SiO3 Al2(CO3)3 NH4OH (NH4)2CrO4 IN CLASS ONLY!

Naming and Writing Formulas for Molecular Compounds 9.3

Binary Molecular Compounds Remember Binary ionic compounds are composed of two elements, a metal and a nonmetal Binary molecular compounds are composed of two elements, both nonmetals and ARE NOT IONS (share valence electrons)

Naming Binary Molecular Compounds Use prefixes when naming binary molecular compounds The prefixes tell the number of each type of atom present in the molecule You MUST MEMORIZE the prefixes on page 281 in the blue book or page 269 in the red book!

Naming Binary Molecular Compounds Key Question (1 of 2) What are the guidelines used to write the name of a binary molecular compound? Write the names of the elements in the order listed in the formula Use prefixes accordingly If there is just one atom of the first element omit the prefix mono- The vowel at the end of a prefix is sometimes dropped when the name of the element begins with a vowel End the name of the second element with the suffix -ide

Practice Naming Binary Molecular Compounds Name the following binary molecular compounds: Model CO2 CO H2O PCl3 IN CLASS ONLY!

Practice Naming Binary Molecular Compounds Name the following binary molecular compounds: N2O Cl2O8 CS2 S2Cl2 IN CLASS ONLY!

Writing Formulas for Binary Molecular Compounds Key Question (2 of 2) What are the guidelines used to write the formula of a binary molecular compound? First use the prefixes in the name to tell the subscript of each element in the formula. Then write the correct symbols for the two elements with the appropriate subscripts

Practice Writing Formulas for Binary Molecular Compounds Write formulas for these binary molecular compounds: Model Dinitrogen monoxide Carbon tetrachloride Phosphorus pentabromide IN CLASS ONLY!

Practice Writing Formulas for Binary Molecular Compounds Write formulas for these binary molecular compounds: Tetraphosphorus trisulfide Disulfur dichloride Iodine heptafluoride IN CLASS ONLY!

Naming and Writing Formulas for Acids and Bases 9.4

Names and Formulas of Acids Acid is a compound that contains one or more hydrogen atoms and produces hydrogen ions ( H+)when dissolved in water Most acids have the H+ ion written first, hydrogen is acting as a metal in acids, this is the main way to identify an acid

Names and Formulas of Acids Key Question (1 of 2) How do you determine the name of an acid? Anion ends in –ide, the acid name will begin with hydro- and end in –ic, then write the word acid Example: chloride  hydrochloric acid Anion ends in –ite, the acid name is the stem of the anion with the suffix –ous, then write the word acid Example: phosphite  phosphorous acid Anion end in –ate, the acid name is the stem of the anion with the suffix –ic, then write the word acid Example: phosphate  phosphoric acid

Practice Naming Acids Name the following compounds as acids: Model HNO3 HF H2SO3 IN CLASS ONLY!

Practice Naming Acids Name the following compounds as acids: H2S HNO2 HCN HClO3 IN CLASS ONLY!

Writing Formulas of Acids Key Question How do you write the formula of an acid? Use the rule for writing the name of the acid in reverse. Then balance the charges just as you would for any ionic compound.

Practice Writing Formulas of Acids Write the formulas for the following acids: Model Hydrobromic acid Carbonic acid Sulfurous acid IN CLASS ONLY!

Practice Writing Formulas of Acids Write the formulas for the following acids: Hydrochloric acid Sulfuric acid Phosphorous acid IN CLASS ONLY!

Names and Formulas of Bases Base is typically an ionic compound that produce hydroxide ions (OH-) when dissolved in water Key Question How do you determine the name and formula of a base? Same as other ionic compounds Cation then the anion

Practice Naming and Writing Formulas for Bases Write the formulas of names for the following compounds: Refer to you 9.1 notes LiOH Lead (II) hydroxide Magnesium hydroxide Al(OH)3 IN CLASS ONLY!

The Laws Governing How Compounds Form 9.5

The Laws of Definite and Multiple Proportions These laws describe the proportions in which elements combine to form compounds The rules for naming and writing formulas obey these rules

Law of Definite Proportions Law of definite proportions states that in samples of any chemical compound, the masses of the elements are always in the same proportions Key Question How is the law of definite proportions consistent with Dalton’s atomic theory? Dalton believed that atoms would combine in simple-whole number ratios; therefore, if the atoms are fixed, then their masses must also be fixed

Law of Multiple Proportions Law of multiple proportions states that whenever that 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 Examples page 290 CuCl CuCl2