1. Writing Chemical Formulas

2. Prefix System mono= 1 di = 2 tri = 3 tetra = 4 penta= 5 hexa = 6 hepta= 7 octa= 8 non= 9 dec = 10 dinitrogen trisulfide N2S3N2S3

3. Writing Chemical Formulas Stock System *The Roman numeral is equal to the positive oxidation number of the element before it. *Roman numerals are only used with elements that have more than one possible positive oxidation number. copper II sulfide Cu +2

4. Writing Chemical Formulas "ide endings" Names ending with the letters "ide" are usually elements with negative oxidation numbers. Examples: oxide - O 2- hydride - H 1- sulfide - S 2- chloride - Cl 1- Exceptions: Hydroxide - OH 1- Peroxide - O 2 2- Cyanide - CN 1- "ate" and "ite" endings Names ending with the letters "ate" or "ite" are polyatomic ions (see Reference Table E).

5. Writing Chemical Formulas Ex. (1) aluminum chloride _______________  _______________ Ex. (2) ammonium chloride _______________  _______________ Ex. (3) iodine trichloride _______________  _______________ Ex. (4) chlorine gas _______________  _______________ Al Cl +3 31 AlCl 3 NH 4 Cl +1 NH 4 Cl ICl tri 3 ICl 3 Cl 2 Cl 2 11

6. Writing Chemical Formulas Ex. (5) chloride ion _______________  _______________ Ex. (6) calcium hydroxide _______________  _______________ Ex. (7) copper II hydroxide _______________  _______________ Ex. (8) dinitrogen pentoxide _______________  _______________ Cl ide ion Cl 1- CaOH +2 21 Ca(OH) 2 CuOH +2 II 21 Cu(OH) 2 dipent NO 25 N2O5N2O5

7. Writing Chemical Formulas Ex. (9) nitrogen V oxide _______________  _______________ Ex.(10) hydrogen sulfide _______________  _______________ Ex.(11) barium sulfate _______________  _______________ Ex.(12) barium acetate _______________  _______________ NO V +5-2 52 N2O5N2O5 HS +1 ide -2 12 H2SH2S BaSO 4 +2-2 BaSO 4 BaC2H3O2C2H3O2 +2 21 Ba(C 2 H 3 O 2 ) 2 2211

8. Writing Chemical Formulas Ex.(13) lead IV oxide _______________  _______________ Ex.(14) potassium chlorate _______________  _______________ Ex.(15) lead II iodide _______________  _______________ Ex.(16) lithium carbonate _______________  _______________ PbO IV +4-2 42 21 PbO 2 KClO 3 +1 1 1 KClO 3 PbI II +2 2 1 PbI 2 LiCO 3 +1-2 12 Li 2 CO 3

9. Ex.(17) zinc bromide _______________  _______________ Ex.(18) sodium peroxide _______________  _______________ Ex.(19) tin II nitrate _______________  _______________ Ex.(20) sodium thiosulfate _______________  _______________ NO 3 -2 O2O2 Writing Chemical Formulas ZnBr +2 21 ZnBr 2 1 Na 2 O 2 Na +1 2 Sn II +2 21 Sn(NO 3 ) 2 S2O3S2O3 Na +1-2 12 Na 2 S 2 O 3

10. Writing Chemical Formulas Ex.(21) sulfur dioxide _______________  _______________ Ex.(22) nitrogen monoxide _______________  _______________ Ex.(23) sodium carbonate _______________  _______________ Ex.(24) cobalt II chlorate _______________  _______________ SO di 12 SO 2 mon NO 11 NO CO 3 Na +1-2 12 Na 2 CO 3 ClO 3 Co +2 II 21 Co(ClO 3 ) 2

11. Writing Chemical Formulas Ex.(25) silver sulfide _______________  _______________ Ex.(26) sodium carbonate _______________  _______________ Ex.(27) nitrite ion _______________  _______________ Ex.(28) nitrogen IV oxide _______________  _______________ AgS +1-2 12 Ag 2 S -2 CO 3 Na +1 1 2 Na 2 CO 3 ion NO 2 NO 2 1- IV NO NO 2 +4-2 4221

12. Writing Chemical Formulas Ex.(29) hydrogen peroxide _______________  _______________ Ex.(30) nickel II fluoride _______________  _______________ Ex.(31) barium chloride _______________  _______________ Ex.(32) carbon disulfide _______________  _______________ HO2O2 +1-2 12 H2O2H2O2 FNi +2 II 12 NiF 2 BaCl +2 2 1 BaCl 2 di CS 12 CS 2

13. Writing Chemical Formulas Ex.(33) ammonium nitrate _______________  _______________ Ex.(34) sodium dichromate _______________  _______________ FIN! NH 4 NO 3 +1 11 NH 4 NO 3 Cr 2 O 7 Na +1-2 1 2 Na 2 Cr 2 O 7 chromatedi