Writing Formulas and Naming Compounds

Binary Compounds Compounds that are made up of only 2 elements Two types of binary compounds: Ionic Compounds – metals and nonmetals (Ex: NaCl, MgBr2, K2O) Covalent Compounds – 2 nonmetals (Ex: CO2, H2O, SO3)

Practice – Ionic or Covalent? NO2 P2O4 Fe2O3 CaF2 covalent covalent ionic ionic

Naming Covalent Compounds 1. Use prefixes to indicate the number of each element mono – 1 di – 2 tri – 3 tetra – 4 penta – 5 hexa – 6 hepta – 7 octa – 8 nona – 9 deca – 10

Naming Covalent Compounds 2. Name the first element. If you have only one atom of the first element, do NOT use the prefix mono-. 3. Name the second element with prefixes. Change the ending to “-ide.”

Naming Covalent Compounds - Practice SO3 N2O4 CCl4 5. H2O carbon dioxide sulfur trioxide dinitrogen tetroxide carbon tetrachloride dihydrogen monoxide

Writing Covalent Compounds PCl3 phosphorus trichloride nitrogen dioxide sulfur hexabromide 4. diphosphorus pentoxide NO2 SBr6 P2O5

Naming Ionic Compounds Name the first element (metal) Name the second element (nonmetal) and change the ending to ”-ide” NO PREFIXES!!!

Naming Ionic Compounds - Practice NaCl CaF2 Ag2O AlBr3 5. ZnS sodium chloride calcium fluoride silver oxide aluminum bromide zinc sulfide

Writing Ionic Formulas Ionic compounds are composed of a positive ion called a cation and a negative ion called an anion. Write the metal ion first ( + ion: cation) Write the nonmetal last ( - ion: anion) Balance the charges! Charges must add up to zero to form a neutral compound.

Writing Ionic Formulas To determine the charge: You can look at the position of the element on the periodic table to determine the charge of the element when it forms an ion There is a difference between a neutral element (K) and an ion (K+)

Periodic Table Charges

Writing Ionic Compound Formulas 1. sodium chloride NaCl 2. calcium chloride CaCl2 Na+ Cl- Ca+2 Cl- Cl-

Writing Ionic Compound Formulas 3. aluminum chloride Al+3 Cl- AlCl3 Cl-

Writing Ionic Compound Formulas 4. potassium bromide K+ KBr 5. potassium oxide K2O Br- O-2

Writing Ionic Compound Formulas 6. aluminum oxide Al+3 Al2O3 O-2 O-2 O-2

Ionic Compounds with Roman Numerals The roman numeral gives the charge of the metal ion. Ex: Fe(II) Fe+2 Fe(III) Fe+3 Transition metals need roman numerals in the name. Pb and Sn need roman numerals because they have charges of +2 and +4. Ag and Zn do NOT need roman numerals because Ag is always +1 and Zn is always +2.

Ionic Compounds with Roman Numerals – Write the Formula nickel (II) bromide lead (IV) oxide 3. iron (III) sulfide NiBr2 PbO2 Fe2S3

Ionic Compounds with Roman Numerals – Name the Following CrCl3 FeO SnCl4 4. Cu2O chromium (III) chloride iron (II) oxide tin (IV) chloride copper (I) oxide

Review: Write the Formula SrF2 strontium fluoride chromium (III) oxide sulfur hexabromide iron (III) sulfide carbon disulfide Cr2O3 SBr6 Fe2S3 CS2

Review: Name the Following. potassium selenide K2Se CaI2 NiCl2 PCl3 BaNa2 calcium iodide nickel (II) chloride phosphorus trichloride banana 

Naming Compounds with Polyatomic Ions Name the metal Name the polyatomic ion Use roman numeral if needed

Naming Polyatomic Ions – Practice: Name the Compound magnesium carbonate MgCO3 Na2SO4 Cu(OH)2 4. Zn(C2H3O2)2 sodium sulfate copper (II) hydroxide zinc acetate

Naming Polyatomic Ions – Practice: Write the Formula Al(NO3)3 aluminum nitrate ammonium sulfite iron (III) chlorate 4. calcium phosphate (NH4)2SO3 Fe(ClO3)3 Ca3(PO4)2

Review: Covalent compounds are made up of nonmetals only. Use prefixes in the names of covalent compounds. Covalent compounds do not have charges! Ionic compounds are made up of a metal and a nonmetal. Balance the charges when you write a formula for ionic compounds. Never use prefixes in the names of ionic compounds!