1 / 20

Guide to Naming Ionic Compounds

Learn how to name cations and anions, when to use Roman numerals, and handle polyatomic ions in ionic compound naming. Understand charges based on valence electrons and differentiate between different anions. Helpful tips provided for easy understanding.

allen-perez
Télécharger la présentation

Guide to Naming Ionic Compounds

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. Guide to Naming Ionic Compounds February 18

  2. Naming Ions and Ionic Compounds • Cations (+) • The name of a cation is the same as the name of the element • Find name either on the periodic table or from memory • A few cations need Roman numerals with the name

  3. Cations that need Roman Numerals • All d-block elements except Ag+, Zn2+, Cd2+ • Some p-block elements Zn2+ Ag+Cd2+

  4. Roman Numerals • I, II, III, IV, V, VI, VII, IX, X, etc. • Some cations need Roman numerals because they can form more than one ion by losing different numbers of valence electrons • The numeral tells you the charge of the ion. For example: • Symbol Cation name • Ti2+ titanium (II) • Ti4+ titanium (IV)

  5. Exceptions • All d-block elements need Roman numerals except Ag+, Zn2+, Cd2+ • Silver, zinc, and cadmium will only form one ion. The charge will always be the same for these three cations. • Symbol Cation name • Ag+ silver NOT: Silver (I) • Zn2+ zinc NOT: Zinc (II) • Cd2+ cadmium NOT: Cadmium (II)

  6. Examples: Name to Symbol All cations have positive charges • Cation nameSymbol • Sodium Na+ • Hydrogen H+ • Vanadium (III) V3+ • Tin (II) Sn2+ We know the charge of the sodium and hydrogen cations by looking at a periodic table The Roman numeral tells us the charge of the vanadium and tin ions

  7. Note on Determining the Charge • Depends on number of valence electrons • How many electrons does the atom need to gain or loose to reach a full valence shell? • Will loose to reach 0 electrons or • Will gain to reach 8 electrons • If it looses electrons, the ion is positive • If it gains electrons, the ion is negative

  8. Another way to think about ionic charge…

  9. Examples: Symbol to Name Sr2+ and K+ do not need Roman numerals because they are in the s-block • Symbol Cation name • Sr2+ Strontium • Cd2+ Cadmium • Cu2+ Copper (II) • Pb3+ Lead (III) • Pb2+ Lead (II) • K+ Potassium Cadmium does not need a Roman numeral because it is one of the three d-block exceptions The charge of the ion symbol tells us what Roman numeral to write in the name. Copper and lead need Roman numerals because they are found in the d-block and lower-left p-block and form more than one ion.

  10. Naming Ions and Ionic Compounds • Anions (-) • The name of a anion is similar to the name of the element • Find name either the periodic table or from memory • Drop the ending of the element name • Add –ide to the stem • NOTE: If the anion’s name ends in –ide and is NOT cyanide (CN-), hydroxide (OH-), or peroxide (O22-), it will be an ion of an element you find on the periodic table

  11. Examples: Name to Symbol All anions have negative charges • Cation nameSymbol • Bromide Br- • Oxide O2- • Nitride N3- • All the names end in –ide: • Bromine bromide • Oxygen  Oxide • Nitrogen  Nitride We know the charge of the anions by looking at a periodic table

  12. Another way to think about ionic charge…

  13. Examples: Symbol to Name • Symbol Element nameAnion name • S2-sulfur Sulfide • Cl-chlorine Chloride • P3-phosphorous Phosphide

  14. Polyatomic Ions • A molecule with a charge • You will need to memorize the names • They behave just like monotomiccations and anions

  15. Examples: Name to Formula • Ion nameFormula • Oxalate C2O42- • Chlorate ClO3- • Acetate CH3COO- • Ammonium NH4+

  16. Examples: Formula to Name • Ion nameFormula • O22- Peroxide • CH3COO- Acetate • Cr2O72- Dichromate • AsO43- Arsenate • MnO4- Permanganate

  17. Helpful Tip 1: Hints in names • Look for clues in the polyatomic ion names • Example: • Cr2O72-Dichromate • Chromate sounds like chromium • Di means two • Dichromate has two chromiums in it

  18. Helpful Tip 2: -ate vs. –ite • If two similar ions have names that end in –ate and –ite, -ate will have more oxygen • ClO3- Chlorate3oxygens • ClO2- Chlorite2oxygens • NO3- Nitrate3oxygens • NO2- Nitrite2oxygens • SO42-Sulfate4oxygens • SO32- Sulfite3oxygens

  19. Helpful Tip 3: Per- and Hypo- • Per-: 1 more oxygen, same charge • Hypo-: 1 less oxygen, same charge • ClO4- Perchlorate 4 oxygens • ClO3- Chlorate3oxygens • ClO2- Chlorite2oxygens • ClO- Hypochlorite 1 oxygen

More Related