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Writing and Naming Chemical compounds

Writing and Naming Chemical compounds. Oxidation Numbers. Same as the charge for a monatomic ion (ex. Fluorine is -1, sodium is +1)

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Writing and Naming Chemical compounds

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  1. Writing and NamingChemical compounds

  2. Oxidation Numbers • Same as the charge for a monatomic ion (ex. Fluorine is -1, sodium is +1) • In a covalent compound, the electrons are divided equally if the atoms are the same, or are assigned to the more electronegative atom if they are different (H2O has H+1 and O-2 oxidation states) • Sum is equal to zero in a compound

  3. Naming Chemical Compounds

  4. Chemical formulas • Show the kinds and numbers of atoms in the smallest representative unit of the substance • Molecular formula – neutral group of atoms, covalently bonded ex. H2O • Formula unit – lowest whole number ratio of ions in an ionic compound ex. NaCl

  5. Metals • Form positive ions • Are written first in a compound • Just use their element names

  6. Transition Metals • Have more than one charge • Need to have Roman numerals added to their names to show charge • OR need suffixes to show lower or higher charge (-ous,-ic-)

  7. Nonmetals • Form negative ions (or have negative oxidation states) • Are written second in a compound name • Change the element name by adding –ide suffix

  8. Naming Binary Ionic Compounds • Binary means two elements • Ionic – is a salt, composed of a metal ion and a nonmetallic ion • The element with the positive ionic charge is written first (Cation = metallic) • The negative ion element name gets an ending of “ide” (Anion = nonmetallic)

  9. ZnS KCl BaO CuBr2 Zinc sulfide Potassium chloride Barium oxide Copper II bromide 45. Name Binary Ionic Compounds

  10. Writing formulas • Use name to identify symbol and charge for each part of the compound (Roman numbers tell charge) • The sum of the charges for a compound must be zero • Determine how many of each element or polyatomic ion you need

  11. Writing Formulas con’t • Use subscripts if you need more than one of any part • If there is more than one polyatomic ion, use parentheses and put the subscript outside the parentheses • Example magnesium nitrate • Mg +2 NO3 – becomes Mg (NO3)2

  12. Ionic Compounds

  13. Sodium iodide Stannous fluoride Potassium sulfide Calcium iodide NaI SnF2 K2S CaI2 # 44 Binary Ionic compounds

  14. Binary Ionic Examples • Copper I oxide • Copper II oxide • Ferrous chloride • Ferric chloride • Lead II sulfide • Lead IV sulfide

  15. Polyatomic ions • Atoms form charged groups • Most are negatively charged • They combine with other elements or polyatomic ions to form compounds • They stay together (like a close group of friends)

  16. Polyatomic con’t • You need to learn their names • Just use their names (no prefixes or suffixes) • Fewer oxygens have –ite • More oxygens have –ate • NH4OH is ammonium hydroxide

  17. Molecules • Nonmetals form molecules with each other • They share electrons • They may form more than one compound with each other • Use prefixes to tell how many of each element

  18. Mono = 1 Di = 2 Tri = 3 Tetra = 4 Penta = 5 Hexa = 6 Hepta = 7 Octa = 8 Nona = 9 Deca = 10 Prefixes and meanings

  19. Use of prefixes • The least electronegative element is written first – use the name of this element • The second element is named using the –ide ending • Use prefixes to show how many of each element • Do not use –mono if there is only one of the first element

  20. CO is carbon monoxide CO2 is carbon dioxide Note: since there is only one carbon, no prefix is used N2H4 is dinitrogen tetrahydride Molecule examples

  21. Hydrates • These prefixes can also be used for hydrates(compounds that contain water molecules) • Example CuSO4. 5 H2O is : copper II sulfate penta hydrate

  22. Naming Acids Acids are compounds that give off H+ ions in solution (aq)

  23. Binary Acids • Hydrogen and one nonmetal • Basic formula of HX • Add –hydro as a prefix • Add – ic as a suffix • Example: hydrogen and chloride ion • HCl is named hydrochloric acid

  24. Acids with polyatomic anions • The –ate ending becomes –ic • Example: NO3- is nitrate ion • Combined with hydrogen ion in solution it becomes HNO3 • This compound is named nitric acid

  25. Polyatomic (oxyacids) con’t • The –ite ending becomes –ous • NO2- is nitrite ion • It forms nitrous acid which is written HNO2

  26. HCl H2SO4 HNO3 HC2H3O2 H3PO4 H2CO3 Acids to Know

  27. Chapter 5 Review Problems P. 137

  28. Lithium hydrogen sulfate Chromium III nitrite Mercury II bromide Ammonium dichromate LiHSO4 Cr(NO2)3 HgBr2 (NH4)2Cr2O7 # 47 Write the formulas

  29. OF2 Cl2O8 SO3 P4O10 Oxygen difluoride Dichlorine octoxide Sulfur trioxide Tetraphosphorus decoxide 50. Name the binary molecules

  30. Nitrogen trifluoride Disulfur dichloride Dinitrogen tetroxide Phosphorus pentachloride NF3 S2Cl2 N2O4 PCl5 51. Write formulas for binary molecules.

  31. HCl HNO3 Sulfuric acid Acetic acid Hydrochloric acid Nitric acid H2SO4 HC2H3O2 52. Give the name or formula for these acids.

  32. Potassium permanganate Calcium hydrogen carbonate Dichlorine heptoxide Trisilicon tetranitride Skip Phosphorus pentabromide Carbon tetrachloride KMnO4 Ca(HCO3)2 Cl2O7 Si3N4 NaH2PO4 PBr5 CCl4 56. Write the formulas

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