Ionic Compounds: Non-Binary Compounds or Polyatomic Compounds

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Ionic Compounds Non-Binary Compounds or
Polyatomic Compounds

• Science 10
• Chemistry Unit

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Reminders

• Bring your textbook to class everyday this week
• Make up Quizzes ProbesWednesday Lunch Time
• Review 1/NomenclatureDue tomorrow
• Phones Off Invisible
• In-Class Assignments (1 2)Place in Basket
• Thursdays (Library) Research ProjectBasket

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Ternary Ionic CompoundsPolyatomic Ions

• Can be found on the back of your coloured
  periodic table.
• Polyatomic ions are ions that have more than one
  elementpoly means more than one or many.
• As you can see, the charges of the polyatomic
  ions vary from positive to negative values
  (cations and anions).
• You can usually tell that you have a polyatomic
  ion from the ending an ate, ite, ium, and
  ide ending as in cyanide and hydrogen sulphide.

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Nomenclature

• Is very straight forward.
• Write the name of the cationthe positive ion as
  is.
• Write the name of the anionthe negative
  polyatomic ion as is.
• If the anion is a non-metal, make sure the ending
  is -ide.
• Example
• NH4Cl ammonium chloride
• (NH4)2CO3 ammonium carbonate

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Compound Formula Compound Name
BaCO3
Sr(C2H3O2)2
NaOH
NH4Cl
Fe(NO3)3
CdSO4
Ca3(PO4)2
Ag2CO3
KC2H3O2 (same as CH3COO-)
Fe(OH)2
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Formulae Writing

• Is a little more complicated
• We just follow the strategy we have been using
  until now.
• The overall charge for an ionic compound must
  always equal zero!

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Example 1 Write the formula for sodium sulfate

• Strategy
• Write the ions and their charges
• Ask yourself, is the overall charge equal to
  zero? If not make it so...use the crossover
  method.
• Remember to keep the elements of the polyatomic
  ion together, use brackets around them.
• Write the formula with just the elements and
  subscripts...no superscripts or charges.

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Example 2 Write the formula for calcium phosphate

• Strategy
• Write the ions and their charges
• Ask yourself, is the overall charge equal to
  zero? If not make it so...use the crossover
  method.
• Remember to keep the elements of the polyatomic
  ion together, use brackets around them.
• Write the formula with just the elements and
  subscripts...no superscripts or charges.

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Example 3 Write the formula for ammonium
bicarbonate (or hydrogen carbonate)

• Strategy
• Write the ions and their charges
• Ask yourself, is the overall charge equal to
  zero? If not make it so...use the crossover
  method.
• Remember to keep the elements of the polyatomic
  ion together, use brackets around them.
• Write the formula with just the elements and
  subscripts...no superscripts or charges.

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Example 4 Write the formula for hydrogen cyanide

• Strategy
• Write the ions and their charges
• Ask yourself, is the overall charge equal to
  zero? If not make it so...use the crossover
  method.
• Remember to keep the elements of the polyatomic
  ion together, use brackets around them.
• Write the formula with just the elements and
  subscripts...no superscripts or charges.

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Name of Compound Element or Polyatomic Cation Element or Polyatomic Anion Compound Formula
Aluminum Carbonate
Aluminum Acetate
Aluminum Hydroxide
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Name of Compound Element or Polyatomic Cation Element or Polyatomic Anion Compound Formula
Ammonium Fluoride
Beryllium Nitrate
Magnesium Sulfate
Calcium Phosphate
Strontium Carbonate
Barium Acetate
Magnesium Hydroxide
Ammonium Sulfide
Aluminum Nitrate
Aluminum Phosphate