Ionic bonding binary
- 1. Ionic Bonding - Binary by S. Sherman
- 2. Composition Ionic compounds consist of metal cations bonded with nonmetal anions Transfer of electrons Electrons lost by cation are gained by anion The cation and anions surround each other Smallest particle is a formula unit
- 3. Properties (of an ionic compound) Solid state Tend to be crystalline High melting points Electrically neutral Ionic bonds are very strong High electronegativity differences Formation of ionic bond is always exothermic
- 4. Review Cations are positive ions formed from the loss of electrons Anions are negative ions formed from the gain of electrons
- 5. Oxidation States Cations with only one oxidation number are named with the name of the element followed by the word ion (groups 1, 2, 13,14)* *Note: need to know that lead (Pb) and tin (Sn) have multiple charges (both can be 2+ or 4+) Carbon in group 14 does not form ions - it forms covalent bonds (share) instead.
- 6. Cations with multiple oxidation states ( transition metals ) are named with the metal name followed by a roman numeral representing the oxidation state and the word ion *Note: Silver is always +1, Cadmium and Zinc are always +2 : learn these transition metal exceptions!
- 7. Review Nonmetal ions are named with the nonmetal name followed by an –ide Sulfur sulfide, phosphorous phosphide, nitrogen nitride etc.
- 8. Review – Name these ions Na + Ca 2+ Al 3+ Fe 3+ Fe 2+ Pb 2+ Zn 2+
- 9. Answers: Sodium ion Calcium ion Aluminum ion Iron (III)ion Iron (II)ion Lead (II) ion Zinc ion
- 10. Review – Name these: P 3- S 2- N 3- O 2- F - Cl - I-
- 11. Answers (make sure you spelled correctly!): Phosphide ion Sulfide ion Nitride ion Oxide ion Fluoride ion Chloride ion Iodide ion
- 12. Writing Ionic Formulas Objectives: balance the electrons lost and gained Write formula with lowest possible ratio with this balance of electron transfer Final formula is neutral
- 13. Two types of Ionic Bonding Binary ionic bonding: Composed of two elements One cation and one anion – both monatomic Ternary ionic bonding: Composed of three or more elements One cation and one anion – must contain at least one polyatomic ion (will discuss later)
- 14. Writing Formulas - Binary Sodium chloride comes from the sodium atom and chlorine atom combined (forming ions in process): Sodium ion Na + (losing one electron) Chloride ion Cl - (gaining one electron) The electron lost by the sodium atom to transferred to the chloride ion
- 15. Picture Explanation (use your dot diagrams) Copy from board! Na Cl Final chemical formula: NaCl (1:1 ratio)
- 16. Barium Chloride – writing formula Composed of barium atom combined with chlorine atom (forming ions in process) Barium ion Ba 2+ (loses two electrons) Chloride ion Cl - (gains one electron) You need two of the chlorine atoms to each gain one electron to combine with one atom of barium losing two electrons to balance the transfer of electrons!
- 17. Picture Explanation Ba Cl Cl Final formula: BaCl 2 (1:2) ratio
- 18. Aluminum Sulfide Comes from the aluminum atom combining with the sulfur atom (forming ions in process): Aluminum ion Al 3+ (loses 3 electrons) Sulfide ion S 2- (gains 2 electrons) Must balance the charges – find lowest common denominator need to lose 6 and gain 6 total Need 2 Al atoms each losing 3 electrons to balance with 3 sulfur atoms each gaining 2 electrons!
- 19. Picture Explanation Al S Al S S Final formula Al 2 S 3 (2:3 ratio)
- 20. Practice! Write formula for: Magnesium + Oxygen Sodium + Nitrogen Barium + Phosphorus Aluminum + Bromine 5. Tin (IV) + Sulfur Make columns for: cation, anion, formula and name (will add later) in your notebook
- 21. Elements Cation Anion Formula Magnesium and Oxygen Mg 2+ O 2- MgO Sodium and Nitrogen Na + N 3- Na 3 N Barium and Phosphorus Ba 2+ P 3- Ba 3 P 2 Aluminum and Bromine Al 3+ Br - AlBr 3 Tin (IV) and Sulfur Sn 4+ S 2- SnS 2
- 22. Writing Names For formulas with cations that only have one charge, just write the name of the two ions without the word ion For formulas with cations that have multiple charges (transition metals) you need to look at the charge on the anion to determine the charge of the cation
- 23. Examples MgO magnesium oxide (only 1 possible charge so no roman numeral) MnO manganese (II) oxide (multiple charges need roman numeral) Oxide ion is O 2- , and there is a 1:1 ratio of ions in the formula MnO therefore the charge on Mn must be +2 to balance the charge and get that formula
- 24. Examples MnO 2 manganese (IV) oxide Oxide ion is O 2- (gains 2 electrons) and you have two atoms of oxygen in the formula so the total electrons gained is x 2 = 4 Therefore, the one atom of manganese needs to lose 4 electrons!
- 25. Picture example MnO comes from Mn O +2 cation = manganese (II) MnO 2 comes from Mn O O + 4 cation = manganese (IV)
- 26. Naming Practice: 1-5. Go back and name the formulas on the previous practice! Also Name: 6. ReS 3 7. CaS 8. PbO 9. Ag 2 O 10. FeF 3
- 27. Answers – Check your spelling! Elements Cation Anion Formula Name Magnesium and Oxygen Mg 2+ O 2- MgO Magnesium Oxide Sodium and Nitrogen Na + N 3- Na 3 N Sodium Nitride Barium and Phosphorus Ba 2+ P 3- Ba 3 P 2 Barium Phosphide Aluminum and Bromine Al 3+ Br - AlBr 3 Aluminum Bromide Tin (IV) and Sulfur Sn 4+ S 2- SnS 2 Tin (IV) Sulfide
- 28. Answers (spelling counts!): Formula Cation Anion Name ReS 3 Re 6+ S 2- Rhenium (VI) Sulfide CaS Ca 2+ S 2- Calcium Sulfide PbO Pb 2+ O 2- Lead(II) Oxide Ag 2 O Ag + O 2- Silver Oxide FeF 3 Fe 3+ F - Iron (III) Fluoride
- 29. Independent Practice Complete the binary ionic bonding practice handout – by yourself! You should only use the periodic table you were provided.