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9-1 Notes Naming Ions. Monatomic Ions  Ionic compounds consist of a positive ion (a metal) bonded to a negative ion (a nonmetal)  Ex. KBr  Monatomic.

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Presentation on theme: "9-1 Notes Naming Ions. Monatomic Ions  Ionic compounds consist of a positive ion (a metal) bonded to a negative ion (a nonmetal)  Ex. KBr  Monatomic."— Presentation transcript:

1 9-1 Notes Naming Ions

2 Monatomic Ions  Ionic compounds consist of a positive ion (a metal) bonded to a negative ion (a nonmetal)  Ex. KBr  Monatomic ions consists of a single atom that has lost or gained electron(s)  Ex. Potassium ion lost an electron, while the Bromide ion gained an electron

3 Cations  Cations are positively charged ions that occur when atoms lose electrons  The # of electrons lost will correspond to the group # on the periodic table  Ex. Sodium in group 1 will lose 1 electron  Naming Cations – the name is the same as the element the ion is formed from  Ex. Sodium forms the sodium cation  Identify the cation of the following elements: Ca, Rb, Al, Li, Sr

4 Anions  Anions are negatively charged ions that occur when atoms gain electrons  Nonmetals in groups 5-7 form anions  The charge is determined by subtracting 8 from the group #  Ex. Oxygen is in group 6, therefore, 6-8 = -2  Naming Anions – the end of the element’s name changes to –ide  Ex. Bromine forms the Bromide anion  Identify the anions of the following elements: P, Se, I, F, N

5 Ions of Transition Metals  Many of the transition metals form more than 1 cation  The charges must be determined from the number of electrons lost  Ex. Iron can lose 2 electrons and form Fe 2+ or it can lose 3 electrons and form Fe 3+  See Table 9.2 p. 255

6 Ions of Transition Metals  There are 2 ways to name these ions  1. Stock System – uses roman numerals to indicate the charge on the ion  Ex. Fe 2+ is Iron (II) while Fe 3+ is Iron (III)  2. Classical name – uses the Latin form of the element and a suffix to indicate the charge  The suffix –ous indicates the lower of the 2 charges  The suffix –ic indicates the higher of the 2 charges  Ex. Fe 2+ is the ferrous ion while Fe 3+ is the ferric ion  A few transition metals only form 1 ion and these are named like all other cations  Ex. Silver (Ag + ), Zinc (Zn 2+ )

7 Polyatomic Ions  Polyatomic ions are composed of more than 1 atom  Ex. Nitrate (NO 3 - ) consists of both nitrogen and oxygen  The names of most polyatomic ions end in -ite or –ate  The use of –ite or –ate as the ending usually depends on the # of Oxygen atoms in the ion  Ex. Nitrate (NO 3 - ) has more oxygen atoms while Nitrite (NO 2 - ) has less oxygen atoms

8 Polyatomic Ions  If the formula for a polyatomic ion begins with an H it includes a H+  The charge is the sum of the two ions  Ex. Hydrogen carbonate (HCO 3 - ) is the sum of H + and CO 3 2-  Most polyatomic ions are negatively charged  The 1 exception is NH 4 + which is ammonium  See Table 9.3 p. 257

9 9-2 Notes Naming and Writing Formulas for Ionic Compounds

10 Naming Binary Ionic Compounds  A binary compound is composed of 2 elements and can either be ionic or molecular  1 st step in naming an ionic compound is making sure it is composed of a monatomic metal cation and a monatomic nonmetal anion  When naming, simply place the cation name first followed by the anion name  Ex. KBr is Potassium bromide, while Na 2 O is sodium oxide  When the cation is a transition metal with more than 1 charge, you must indicate which ion is being used  Ex. Cu 2 O is Copper (I) oxide, while CuO is Copper (II) oxide

11 Writing Formulas for Binary Ionic Compounds  Step 1: Write the symbol of the cation and then the anion.  Step 2: Add whatever subscripts are needed to balance the charges  Make sure the subscripts are reduced  There are two methods to balance charges  1. Find the least common multiple of the charges  2. The crisscross method: the numerical value of the charge of each ion is crossed over and becomes the subscript for the other ion  Write the formulas for the following: Iron (III) oxide and Calcium bromide

12 Compounds with Polyatomic Ions  Naming ionic compounds with polyatomic ions is the same as binary compounds  Write the cation first followed by the anion  Name the following: LiCN, AgNO 3, (NH 4 ) 2 C 2 O 4

13 Compounds with Polyatomic Ions  Step 1: Write the symbol of the cation and then the anion.  Step 2: Add whatever subscripts are needed to balance the charges  Step 3 (if needed): If more than 1 polyatomic ion is needed to balance the charges you must use parentheses  Ex. Calcium Nitrate  Write the formulas for the following: Lithium carbonate & Aluminum nitrite

14 9-3 Notes Naming and Writing Formulas for Molecular Compounds

15 Review  How do we do the following?  Name Ionic Compounds  Ex. KBr, Na 3 PO 4, Fe(NO 3 ) 3  Write Formulas for Ionic Compounds  Ex. Sodium nitride, Ammonium oxide, Copper (II) nitrite

16 Naming Binary Molecular Compounds  Binary molecular compounds are composed of molecules, not ions, and consist of 2 nonmetals  Due to various ways of sharing electrons the same elements can be used to make different compounds  Ex. CO and CO 2  How do you name these so you can tell there is a difference?

17 Naming Binary Molecular Compounds  Prefixes are used to represent the number of atoms of each element that can be found in a molecular compound  The Rules:  1. Confirm the compound is molecular  2. Name the elements in the order listed in the formula  3. Use the appropriate prefix to indicate the # of each element (see table 9.4 p. 269)  Exception: Do not use mono- on the 1 st element  4. Change the ending of the 2 nd element to –ide  Name the following: CO, CO 2, N 2 O 5, CCl 4

18 Writing Formulas for Molecular Compounds  Step 1: Write the correct symbols for the two elements  Step 2: Use the prefixes in the name to determine the subscript of each element in the formula  Write the formula for the following: Dinitrogen tetraoxide, Dihydrogen monoxide, Phosphorus pentachloride

19 9-4 Notes Naming and Writing Formulas for Acids and Bases

20 Review  How do we do the following?  Name Ionic Compounds  Ex. (NH 4 ) 3 PO 4, Cr(NO 2 ) 3  Write Formulas for Ionic Compounds  Ex. Potassium sulfate, Iron (III) oxide  Name Molecular Compounds  Ex. CO 2, CCl 4  Write Formulas for Molecular Compounds  Ex. Boron Trichloride, Dinitrogen tetrahydride

21 Naming Acids  An acid is a compound that contains 1 or more hydrogen atoms and produces H + when dissolved in water  The general form of an acid is H n X  n is the subscript indicating how many Hydrogen ions are needed  X is the monatomic or polyatomic anion

22 Naming Acids – The Rules  1. If the anion ends in –ide, the acid name will begin with hydro-. The –ide will be replaced by –ic and followed by acid  Ex. HCl  2. If the anion ends in –ite, the acid name is the stem of the anion with the suffix –ous and followed by acid  Ex. H 2 SO 3  3. If the anion ends in –ate, the acid name is the stem of the anion with the suffix –ic and followed by acid  Ex. HNO 3  Name the following: HF, HNO 2, HMnO 4

23 Writing Formulas for Acids  Use the rules for writing the names of acids in reverse to write the formulas for acids  Remember – add subscripts to balance the formula  Ex. Rule 1 – Hydrobromic acid  Ex. Rule 2 – Phosphorous acid  Ex. Rule 3 – Sulfuric acid  Write formulas for the following: Permanganic acid, Nitrous acid, hydrosulfuric acid

24 Bases  A base is an ionic compound that produces hydroxide ions when dissolved in water  Naming bases and writing formulas is the same as any other ionic compound  Name the following: Ba(OH) 2, KOH  Write the formulas for the following: Strontium hydroxide, Copper (II) hydroxide


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