Nomenclature

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Nomenclature and Stochiometry
By Kimberly Fraser
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L O S E R S
Be Familiar With
G A I N E R S

• Ionic Compounds-
• Formed when a cat ion (metal) and an anion (non
  metal) join together to become neutral

Positive ion, have more protons than
electrons-loose electrons
Negative ion, have less protons than
electrons-gain electrons

• Molecular Compounds-
• Contain nonmetal elements held together by
  covalent bonds.

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Naming Binary Compounds

• Polyatomic Ions-
• Group of atoms that act as a unit and carry a
  charge

1st cat ion ______ anion with ide ending (use
roman numerals when necessary)

• NaNO3 sodium nitrate
• CaSO4 calcium sulfate
• CaSO3 calcium sulfite
• NH4NO3- ammonium nitrate

• Examples-
• Li F -gt LiF -gt Lithium Fluoride
• Mg S -gt MgS -gt Magnesium Sulfide
• Na Br -gt NaBr -gt Sodium Bromide
• Al F -gt AlF3 -gt Aluminum Fluoride

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Using Roman Numerals

• How do you know?
• When there is more than one oxidation state
• Is not in Groups 1,2, or 13
• Usually in the D block and are transition metals
• If transition metals have more than one oxidation
  state, it will then have one ionic charge to
  create the ionic chargeoxidation state
• In these cases you must use a roman numeral to
  state the cations charge

• You use roman numerals if the element is a metal
  and has more than one ionic charge

Examples- FeO -gt iron (II) oxide Fe2O3 -gt iron
(III) oxide MnO -gt manganese (II) oxide CrCl2 -gt
chromium (II) chloride
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Formulas

• Structural Formulas tell us-
• Shows the way the atoms are joined together in a
  molecule.

• Chemical Formulas tell us-
• Elements that make up the compound
• Ratio of the elements in the compound
• Subscripts below the element
• Tell you the number of atoms

Example-
Example- Water-gt H2O-gt 2 hydrogen atoms and one
oxygen atom

• Carbon always forms 4 bonds
• Molecular Models show orientation in 3 dimensions
  so are the best molecular models

• Molecular Formulas tell us-
• Tell you the total number of atoms of each
  element in 1 molecule of the substance

Example- C2H2 -gtAcetylene
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Formula Mass

• Also known as-
• Gram formula mass
• Gram molecular weight
• Molecular weight

• Sum of all the atomic masses in the formula of a
  substance
• Will need to use periodic tables
• Atomic masses based on a scale using C-12

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Binary Molecule Compounds

• Naming Rules-
• Use prefixes to distinguish how many atoms of
  each element are present
• Ending has an ide ending
• Can omit the prefix of one atom in first element

1mono 6hexa 2di 7hepta 3tri 8octa 4tetra
9nona 5penta 10deca

• Examples-
• CO-carbon monoxide
• N2O-dinitrogen monoxide
• Tetraiodine monoxide-I4O
• Carbon tetrafluorideCF4

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Acids
-an acid is a molecular substance that dissolved
in water to produce hydrogen ions
Ternary Acids
Binary Acids

• H plus a polyatomic ion
• Hydro prefix is DROPPED
• If ends with ate the name of the acid ends with
  ic
• If ends with ite the name ends with -ous

• Hydrogen and another element
• H takes the place of metal therefore the prefix
  is HYDRO-

Hydroroot name of anion -ice endingacid
I ate ice cream, it was delicious!

• Examples-
• HCl- hydrochloric acid
• HF- hydrofluoric acid
• Hydrobromic acid
• Hydroiodic acid

• Examples-
• HNO3- nitric acid
• HNO2- nitrous acid

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Moles

• Of any element is the number of atom that element
  which are equal to the atoms in 12.0 grams C-12

6.02 x 1023

• Number of atoms in 1 mole 6.02 x 1023

• Know how to do
• Mass-mole
• Particles-mole
• Volume-mole
• Mixed mole problems

• Mass (g) of 1 mol atomic mass or formula mass

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Spider Diagram for help
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Mass to Mole
Particles to Mole

• Conversion Factor- 6.02 x 1023 particles/mol

• Conversion Factor-Formula Mass

An example of sodium chloride (NaCl) has a mass
of 11.2g. How many moles is that?
How many molecules are in 2 moles of water?
Given 11.2g NaCl Unknown of moles Plan mass
-gt mole Formula g of NaCl/Formula
Massmoles Work Na 1 x 23 23 Cl 1 x 35.5
35.5 58 g/mol 11.2 g NaCl/
58.5 g/mol .191 moles of NaCl
Given 2 moles of water Unknown molecules Plan
mole -gt molecules Formula 2 moles x 6.02 x
1023molecules Work 2.0 mole water x (6.02 x
1023) molecules/mole 1.2 x 1024
molecules water
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Volume to Mole
Mixed Mole

• Conversion Factor- varies

• Conversion Factor-22.4L/mol

A container with a volume of 893L contains how
many moles of air at STP?
A sample of NH3 gas occupys 75.0L at STP. How
many molecules is this?
Given 893L of air Unknown of moles Plan
volume -gt mole Formula 893L/22.4mole Work
893L/22.439.9 mol of air -or- 893L x 1 mol
39.9 mol of air 1 22.4L
Given 75.0L of NH3 Unknown molecules Plan
volume -gt mole -gt molecules Formula 75.0L/22.4 x
6.02 x 1023 Work 75.0L x 1 mol x 6.02 x 1023
22.4L 1 mol 2.0124
2.0224 molecules of NH3

• These problems can go any way across the spider
  diagram this is just one example

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Balancing Equations

• Before moving onto Mole-Mole problems use this
  review for balancing equations

• Steps
• Identify the elements on both sides of the
  equation
• Identify the of atoms on each side
• Pick an element that doesnt have same number of
  atoms on both and increase the coefficient on the
  side where it is smaller than one
• Repeat step 3 until all atoms are equal on each
  side of equation
• Check work and be neat

• Balanced equations have the same number and
  kinds of atoms on both sides the equation

Example- 2 Ag2O -gt 4 Ag__O2 Ag 2 4 Ag 1
2 3 4 O 1 2 O 2
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Mole to Mole
Volume to Volume
How many moles of water are needed to react
completely with 12 moles of sodium according to
the balanced equation that follows? 2Na 2H2O -gt
2NaOH H2
Find volume in liters of hydrogen (H2) that
reacts with the 15.5L of N2
Plan L of N2 -gtmol of N2 -gt mol of H2 -gt L of H2
Work 15.5L N2 x 1 mol N2 x 3 mol H2 x 22.4L H2
22.4L N2 1 mol N2 1 mol H2 46.5 L
H2
Work 12 moles of Na x 2 mol H2O 2
mol Na 12 mol of H2O
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Chemical Reactions
Direct Combination or Synthesis -2 or more
reactants come together to form a single
product AB -gt AB
Double Replacement Reaction -2 compounds as
reactants -2 compounds as products Ax By -gt Ay
Bx
Decomposition Reaction -breaks down into smaller
parts AB -gt A B
Single Replacement Reaction -switches partners A
Bx -gt Ax B
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Limiting Reactants

• Limiting Reactant-
• Reactant that limits the amount of product formed
  in a chemical reaction

• Plan
• g Cu-gtmole Cu-gtmol Ag-gt g Ag
• g AgNO3-gt mol ofAgNO3-gt mol Ag-gt g Ag
• Work
• 1. 3.5g Cu x 1 mol Cu x 2 mol Ag x 108g Ag
• 63.5g Cu 1 mol Cu 1 mol Ag
• 12 grams of Ag
• 2. 6.0g AgNO3 x 1mol AgNO3 x 2mol Ag x 108g
  Ag
• 170g AgNO3 2mol AgNO3 1molAg
• 3.8g Ag
• The Limiting Reactant is AgNO3.

Ex- Cu 2AgNO3 -gt CO(NO3)2 2Ag -Given the
balanced equation where copper reactants with
silver nitrate to produce copper (II) nitrate
plus silver, when 3.5g of Cu is added to a
solution containing 6.0g of AgNO3 what is the
limiting reactant?
-The reactant that produces the least amount is
the limiting reactant.
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Percent Composition and Formula Mass vs. Density
part x 100 whole
DM/V FMD x 22.4L/mol
In water what percent is H and what percent is O2?
Density of a gas is 1.96g with volume at STP,
what is the formula mass?
Formula Mass H 2x1.012.02 O 1x1616 Composition
H 2.0/18.0 x 100 11 0 16/18 x 100 89
18.0grams/mol
FM 1.96g x 22.4L 43.9 g/mol L mol
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Empirical Formulas

• Steps for finding the formula
• -gt grams
• Grams -gt moles
• Divide by the smallest until whole

• Empirical Formula-
• A formula that gives the simplest whole ratio
  of the atoms of the compound.

• To determine the empirical formula you must know
• Mass of each element in sample OR
• Percent composition of compound

Example- Find empirical formula of a substance
that contains 80 C and 20 H. C 80-gt80g x (1
mol/12)6.7mol C/6.71 H 20-gt20g x (1
mol/1.0)20mol H/6.73 C1H3 or CH3
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Molecular Formulas
Molecular formula Formula Mass of Molecule
Empirical
formulas formula mass

• Empirical Formula-
• Tells actual number of atoms that each element
  has
• Always whole number multiples of the empirical
  formula

Example- Find the molecular formula for
CH2O Experiments show that the formula mass of
glucose is 180g/mol (180g/mol)/(30g/mol)6
Multiply 6 to the empirical formula
C6H12O6
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All the material in this unit has now been
reviewed and taught but you should always be
looking material over on www.regentsprep.org,
Mrs. Kilners website, notes, or the textbook to
review for the final exam.