Naming and Writing Formulas

1
Naming and Writing Formulas
2
Binary Ionic or covalent

• Binary compounds
• (Compounds with just two elements)
• ALL Binary compounds have a suffix IDE on the
  second element name
• (hydride, oxide, sulfide nitride.)
• REMEMBER
• Ionic metal and nonmetal
• Covalent nonmetal and nonmetal

3
Naming Binary Covalent compounds

• Numerical prefixes are used to name covalent
  compounds of two elements
• First element can have any prefix EXCEPT mono
• Second element will always have both a prefix
  and a suffix

Number of atoms Prefix 1
Mono 2
Di- 3 Tri-
4 Tetra- 5
Penta- 6
Hexa- 7
Hepta- 8 Octa-
9 Nona- 10
Deca-
4
Binary Covalent

• Binary compounds (Compounds with just two
  elements) H2S
• 1. Name the first element adding the correct
  prefix (IF NEEDED) di Hydrogen
• 2. Name the root of the second element, adding
  the correct prefix mono Sulf
• 3. Add the ending IDE to the root
• dihydrogen monosulfide

5
What about covalent compounds?

• Many covalent compounds are named with prefixes.
• Examples
• CO2
• SO2
• H2O5

carbon dioxide
sulfur dioxide
dihydrogen pentoxide
6
Many covalent compounds are hydrocarbons with
special names

• Examples
• CH4
• C2H6
• C2H4
• C2H2

methane
ethane
ethene
ethyne, or acetylene
7
Naming Ionic Compounds

• Binary compounds (Compounds with just two
  elements) Na2S
• 1. Name the first element - Sodium
• 2. Name the root of the second
  element Sulf
• 3. Add the ending ide to the root
• Sodium Sulfide

ALL binary compounds will end with ide. There
is an exception compounds with ammonium can
also end in ide.. Ammonium Bromide
8
Naming ionic compounds

• The first name is the name of the cation
• Example CaCl2 has first name calcium
• The last name has the name of the anion. (Anion
  names always end in ide unless they are from
  your polyatomic ion chart.)
• Example CaCl2 has last name chloride,
• so CaCl2 is calcium chloride

9
Name these ionic compounds
barium flouride

• 1. BaF2
• 2. K2Se
• 3. CaS
• 4. AlF3
• 5. LiH

potassium selenide
calcium sulfide
aluminum flouride
lithium hydride
10
Atoms and Charges

• Barium Flouride
• BaF2
• Barium 1 atom, 2
• 1 x (2) 2
• Flourine 2 atoms, -1
• 2 x (-1) -2
• (2) (-2) 0
• Charges balance !

• Calcium Phosphide
• Ca3P2
• Calcium 3 atoms, 2
• 3 x (2) 6
• Phosphorous 2 atoms -3
• 2 x (-3) - 6
• (6) (-6) 0
• Charges balance !

11
Ionic Compounds

• Some common Cations
• Name and Symbol Ion charge
• Cesium ion, Cs 1
• Lithium ion, Li 1
• Potassium ion, K 1
• Rubidium ion, Rb 1
• Sodium ion, Na 1
• Barium ion, Ba 2
• Beryllium ion, Be 2
• Calcium ion, Ca 2
• Magnesium ion, Mg 2
• Strontium ion, Sr 2
• Aluminum ion, Al 3

• Some common Anions
• Name and Symbol Ion charge
• Fluorine, F FluorIDE - 1
• Chlorine, Cl ChlorIDE - 1
• Bromine, Br BromIDE - 1
• Iodine, I IodIDE - 1
• Oxygen, O OxIDE - 2
• Sulfur, S SulfIDE - 2
• Nitrogen, N NitrIDE - 3

12
Some cation names must show their charge

• Transition metals may form several different
  cations each with a different charge because they
  have more than one oxidation number
• These cations must have a Roman Numeral in their
  name. The Roman Numeral shows the cations
  charge.

13
Naming Binary Ionic Using Transition metals

• 1. Identify the cation (IF it is a transition
  look at second element)
• 2. Identify the oxidation of the second element.
• 3. Multiply oxidation (of 2nd element) by of
  atoms (for total charges)
• 4. Use this total to identify oxidation of
  transition metal.

14
Formulas with transition metals..

• Fe2O3 - Fe Yikes a transition!
• Look at the element combined with Fe.
• Oxygen forms a -2 ion , if there are 3 atoms each
  with a -2 charge there is a total charge of -6
  .
• So if Iron has 2 atoms, the total charge must
  equal 6.
• Then this iron must be have a 3 oxidation (3
  X 2 6), so it is named Iron (III) Oxide

15
Some Transition Metal Cations

• Ion name Symbol
• Copper (I) Cu 1
• Copper (II) Cu 2
• Iron (II) Fe 2
• Iron (III) Fe 3
• Nickel (II) Ni 2
• Nickel (III) Ni 3
• Lead (II) Pb 2
• Lead (IV) Pb 4
• Mercury (I) Hg 1
• Mercury (II) Hg 2
• Gold ((I) Au 1
• Gold (III) Au 3

• Ion name Symbol
• Chromium (II) Cr 2
• Chromium (III) Cr 3
• Tin (II) Sn 2
• Tin (IV) Sn 4
• Titanium (II) Ti 2
• Titanium (III) Ti 3
• Titanium (IV) Ti 4
• Manganese (II) Mn 2
• Manganese (III) Mn 3
• Manganese (IV) Mn 4
• Manganese (VI) Mn 6
• Manganese (VII) Mn 7

16
Ternary compounds contain 3 elements

• Compounds containing polyatomic ions have charges
  listed on your polyatomic ion chart.

17
Naming non-binary compounds (polyatomics)

• NaNO3
• 1.Use the first element name
• Na - Sodium
• 2. Add the polyatomic name
• CHECK YOUR LIST
• NO3 - Nitrate
• NaNO3 -

Sodium Nitrate
18
Polyatomic Ion Names

• Most normal polyatomic ion names will have a
  suffix of ATE
• ATE suffix indicates Oxygen in formula
• ITE suffix has one less Oxygen atom than the
  normal
• Add a prefix of HYPO - has two less Oxygen atoms
  than normal
• Prefix of PER with normal ADD 1 oxygen atom

19
Example of Polyatomics ate ite hypo - per

• Note Oxidation DOES NOT change
• Regular Chlorate - ClO3
• One less Oxygen Chlorite - ClO2
• Two less Oxygen Hypochlorite ClO
• One more Oxygen Perchlorate - ClO4

20
With transition elements

• You will have to look at oxidation number of the
  polyatomic
• Follow rules for using transition elements

21
Name these..
Magnesium nitrate

• Mg(NO3)2
• Pb(OH)2
• CuCO3
• K3PO4
• NH4Cl

Lead (II) hydroxide
Copper (II) carbonate
Potassium phosphate
Ammonium chloride
22
Check your understanding

• ASSIGNMENTS
• Naming of Non-Binary Compounds
• Naming Compounds (Mixed) Use flow chart
• Binary Covalent prefixes, IDE suffix
• Binary Ionic NO prefixes, IDE suffix
• Ionic with transitions Roman Numerals
• and IDE suffix
• Non-Binary use polyatomic list

23
Names of Acids

• 1. H in binary (an ide) compound acid name
  with prefix Hydro
• HCl (Hydrogen chloride) aka Hydrochloric
  Acid
• 2. H with ate polyatomic, use suffix ic
• HNO3 is nitric acid
• 3. H with ite polyatomic, use suffix ous
• H2SO3 is sulfurous acid

24
Writing Formulas

• Binary Covalent
• Binary Ionic
• Binary Ionic (metals with various oxidation
  numbers)
• Ternary (with polyatomics)

25
Writing Formulas

• General rules to remember
• 1. Ide suffix means only 2 elements
• 2. Use prefixes for covalent (di, tri,)
• 3. Roman numeral IS the oxidation
• 4. Ate, ite suffix or Hypo, per prefix use the
  polyatomic list.
• 5. REMEMBER cation always goes first
• 6. Reduce when possible

26
Quick try.

• Write formulas for binary compounds when given
  the oxidation number
• Na 1 , Cl -1
• NaCl
• Ba 2 , N -3
• 2 X3, -3 x2 so.
• Ba3N2

27
With Polyatomics

• REMEMBER a polyatomic is treated as one
  substance with its own charge.
• Formula for Lithium phosphate
• Lithium 1 Phosphate -3
• Li 1 (PO4) -3
• Least common multiple is 3
• Li 1 x 3 3 (PO4) -3 x1 -3
• Final formula Li3PO4

28
Writing Formulas Binary Covalent

• Look at prefixes to determine number of atoms
  (subscripts)
• Dinitrogen octofluoride
• Di means two nitrogen N2
• Octo means eight fluorine F8
• Formula N2F8

29
Practice writing covalent formulas

• 1. Dinitrogen monoxide
• N2O
• 2. Carbon tetraphosphide
• CP4
• 3. Sulfur difluoride
• SF2

30
Ionic Compounds from name only

• What is the chemical formula for
• aluminum fluoride?
• List symbols oxidation for each ion
• Al 3 F -1
• Identify of atoms to balance the formula -
  need total of 3 negative charges to balance with
  Als 3 positive charges.
• Write chemical formula, using subscripts for of
  atoms for a neutral compound AlF3
• Reduce if possible and leave the charges off

31
Practice makes perfect only if you practice
perfect!

• Write formulas for
• Calcium sulfide
• Ca2 S2-
• CaS
• Potassium oxide
• K1 O2-
• K2O

32
For Transition metals

• REMEMBER the roman numeral tells you the charge
  (oxidation )
• Follow previous steps for writing ionic formulas
• Iron (III) oxide
• This iron has 3 oxidation
• Oxygen has -2
• Formula Fe2O3

33
Practice makes perfect only if you practice
perfect!

• Write formulas for
• Iron (III) sulfide
• Fe3 S2-
• Fe2S3
• Lead (II) phosphide
• Pb2 P3-
• Pb3P2

34
More practice

• 1. oxalate combined with potassium
• K1 C2O42-
• K2C2O4
• 2. barium bromate
• Ba2 BrO31-
• Ba(BrO3)2

35
Check your understanding

• ASSIGNMENTS
• Writing formulas
• Binary with charges given
• Polyatomic with charges given
• Mixed with names only
• Math Skills workbook 9
• Chemistry workbook mixed

36
Or - the easy way..

• Use the criss-cross method
• aluminum fluoride
• Aluminum has a 3 charge
• Fluorine has a -1 charge
• Cross the two
• 3 -1
• Al F
• 1 atom 3 atoms
• Formula for aluminum fluoride is AlF3

37
For Polyatomic ions..

• Use the criss-cross method.
• Calcium nitrate
• Calcium has a 2 charge
• Nitrate has a -1 charge
• Cross the two
• 2 -1
• Ca (NO3)
• 1 atom 2
  atoms
• Formula for calcium nitrate is Ca (NO3)2