Chemical Naming

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Chemical Naming Formula Writing

• How do you do this???

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What are Ionic Compounds?

• Ionic compounds consist of a cation ( ion) and
  an anion (- ion)
• Monotomic cations can be found to the left of the
  staircase
• Monotomic anions can be found to the right of the
  staircase
• Ex NaCl, CaBr2, K3PO4, NH4Cl

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How are Ionic Compounds Bonded?

• Ionic compounds are formed when electrons are
  transferred between the cation and anion
• The cation will lose electron(s) to become stable
  and look like a noble gas
• The anion will gain electron(s) to become stable
  and look like a noble gas

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How is NaCl Formed?
Na has 1 valence electron and Cl has 7 valence
electrons. Na will transfer its 1 valence
electron to Cl so that they can both become
stable and look like noble gases. Na1 now looks
like Ne from the outer shell and Cl-1 now looks
like Ar.
Na
Cl
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What Does an Ionic Formula Represent?

• An ionic formula represents the lowest whole
  number ratio of atoms in a compound
• This ratio is referred to an a formula unit

Na (green) ions will ionically bond with Cl-
(purple) ions in a repeating pattern to form what
is called a crystal lattice. A formula unit is
the lowest whole number ratio of the Na to Cl
atoms which would be 11 ? NaCl.
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Unique Properties of Ionic Compounds?

• Solids at room temperature
• Relatively high melting points (gt300C)
• High solubility in water
• No conductivity as a solid but as an aqueous
  solution or molten, they are conductive
• You must have ions present in order to conduct
  electric current

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What are Molecular Compounds?

• Molecular compounds consist of 2 nonmetals
  located to the right of the staircase
• 2 types polar and nonpolar covalent
• Polar covalent compounds usually are made up of 2
  or more different nonmetals
• Ex H2O, NH3, CO
• Nonpolar covalent compounds usually are made up
  of 2 of the same nonmetals
• Ex Br2, Cl2, O2

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How are Molecular Compounds Formed?

• For polar covalent compounds, electrons are
  unequally shared between the nonmetals to achieve
  noble gas stability
• The higher electronegative element will pull the
  electron(s) its sharing closer to it than the
  less electronegative element
• For nonpolar covalent compounds, electrons are
  equally shared between the nonmetals to achieve
  noble gas stability

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Nonpolar covalent equal sharing of an electron
between 2 F atoms to become more stable and
look like Ne
F2
Polar covalent unequal sharing of an electron
between each of the 2 H atoms and the O atom
allows H to look like He and O to look like Ne.
The electrons are pulled closer to because it
is the more electronegative element
H2O
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What Does a Molecular Formula Represent?

• A molecular formula represents the actual number
  of atoms in a compound

There are 2 H and 1 O atoms in 1 water molecule
There are 3 H and 1 N atoms in 1 ammonia molecule
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Unique Properties of Polar Covalent Compounds?

• Usually liquids or gases at room temperature
• Melting point is lt300C (less than ionic)
• Solubility in water varies
• Not conductive

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Unique Properties of Nonpolar Covalent Compounds?

• Gases at room temperature (exceptions include I2
  solid and Br2 liquid)
• Very low melting point (less than polar covalent)
• No solubility in water
• Not conductive

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What are Metallic Compounds?

• Metallic compounds consist at least one metal
• Ex Cu, Pt, Sn, Pb, Ag
• Metallic compounds made up of more than 1 metal
  are called alloys
• Ex brass (70 Cu 30 Zn), stainless steel,
  pewter, 14K-24K Au

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How are Metallic Compounds Formed?

• Metallic compounds are bonded by a sea of
  electrons that hold the metal cations together

The delocalized electrons do not belong to any
single cation. They swim in the sea, holding
the cations together
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What Does a Metallic Compound Represent?

• Like an ionic formula, metallic formulas also
  represent the lowest whole number ratio of atoms
  in a compound
• This ratio is referred to an a formula unit

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Unique Properties of Metallic Compounds?

• Solids at room temperature (exception Hg liquid)
• Very high melting points (higher than ionic)
• No solubility in water
• Conductive because of the mobile ions swimming in
  the sea of delocalized electrons