1 / 36

Writing Ionic Formulas

Writing Ionic Formulas. Chemical Formulas from Names & Names from Chemical Formulas. Basic Principles. Formulas show smallest whole-number ratio of ions (posititve and negative) in the substance.

jeanine
Download Presentation

Writing Ionic Formulas

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. Writing Ionic Formulas Chemical Formulas from Names & Names from Chemical Formulas

  2. Basic Principles • Formulas show smallest whole-number ratio of ions (posititve and negative) in the substance. • Formulas are correct only if total charges of all ions add to zero (bulk matter is electrically neutral). • Cations (positive) written and named before anions.

  3. Periodic Table of the Elements

  4. +1 Periodic Table of the Elements

  5. Periodic Table of the Elements +2

  6. Periodic Table of the Elements +2 for many; some +1, others +3; several vary

  7. Periodic Table of the Elements -1

  8. Periodic Table of the Elements -2

  9. Periodic Table of the Elements -3

  10. Periodic Table of the Elements +2

  11. Periodic Table of the Elements +3

  12. Periodic Table of the Elements +2 +2 +1

  13. Periodic Table of the Elements No ions for noble gases.

  14. Combining Ions Remember: Charges must add to zero. Na+ with S2- Na+S2- Na+ Na2S Ca2+ and Cl-1 Cl-1 Ca2+ Cl-1 CaCl2 +1 -2 +2 -1 +1 -1

  15. Br-1 Br-1 Al3+ Br-1 Combining Ions Remember: Charges must add to zero. Mg+2 with S2- Mg+2S2- MgS Al3+ and Br-1 +2 -2 AlBr3 +3 -1 -1 -1

  16. Combining Ions Remember: Charges must add to zero. Mg+2 with N3- Mg+2N3- Mg+2 N3- Mg+2 Mg3N2 +2 -3 +2 -3 +2

  17. You Do One… Remember: Charges must add to zero. Ba+2 with I- I- Ba+2I- BaI2 +2 -1 -1

  18. And another… Remember: Charges must add to zero. Al3+ with F- AlF3 +3 -1 -1 -1

  19. Again… Remember: Charges must add to zero. Al3+ with O2- Al2O3 +3 -2 -2 +3 -2

  20. Transition-metal Cations • Named with positive charge as Roman numeral • +1 = (I) • +2 = (II) • +3 = (III) • Only rarely are charges bigger than three.

  21. Transition-metal Cations • Several elements can, under different conditions, form ions with different charges. • Iron is +2 or +3, Iron(II) or Iron(III) • Copper is +1 or +2, Copper(I) or Copper(II) • A given ion will have only one charge; its value depends on how the ion was formed.

  22. Combining Ions Rules are the same; charges add to zero. Chromium(III) with chloride Cr+3Cl- Cl- Cl- CrCl3 +3 -1 -1 -1

  23. Write these formulas… Silver oxide +1 -2 +1 Ag2O

  24. Write these formulas… Iron(III) iodide +3 -1 -1 -1 FeI3

  25. Write these formulas… Copper(II) oxide +2 -2 CuO

  26. Write these formulas… Copper(I) oxide +1 -2 +1 Cu2O

  27. Polyatomic Ions • Multi-atom Ions • Usually are negative • Usually contain oxygen • Names often end in -ite or -ate • Charges and formulas cannot be predicted from Periodic Table

  28. Polyatomic Ions • Nitrate = NO3-1 • One N plus three oxygens; total charge = -1 • Carbonate = CO3-2 • One carbon plus three oxygens; total charge = -2 • Sulfate = SO4-2 • One S plus four oxygens; total charge = -2 • Hypochlorite = ClO-1 • One Cl plus one oxygen; total charge = -1

  29. Good News! • Same rules for writing ionic formulas using ployatomic ions as for “simple ions” • Charges of all ions must add to zero

  30. Combining Ions Rules are the same; charges add to zero. Sodium nitrate Na+1 and NO3-1 NaNO3 +1 -1

  31. Combining Ions Rules are the same; charges add to zero. Sodium carbonate Na+1 and CO3-2 Na2CO3 +1 -2 +1

  32. Combining Ions Rules are the same; charges add to zero. Magnesium nitrate Mg+2 and NO3-1 Mg(NO3)2 +2 -1 -1 Note:where more than one polyatomic ion occurs, it must be enclosed in parentheses. A subscriptalways follows the closed parenthesis.

  33. Write these formulas… Copper(I) carbonate +1 -2 +1 Cu2CO3

  34. Write these formulas… Iron(II) nitrate +2 -1 -1 Fe(NO3)2

  35. Note, this polyatomic ion appears only once and does not have parentheses. Write these formulas… Ammonium phosphate +1 -3 +1 +1 (NH4)3PO4

  36. Names these substances... • Na2SO4 • Cu2S • FeS • Fe2S3 • FeSO4 • Mg3N2 • Mg(NO3)2 Sodium sulfate Copper(I) sulfide Iron(II) sulfide Iron(III) sulfide Iron(II) sulfate Magnesium nitride Magnesium nitrate

More Related