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CHEMISTRY E182019
CH3
Nomenclature of compounds (names and
formula)Mixtures.Balances.
Rudolf Žitný, Ústav procesní a zpracovatelské
techniky CVUT FS 2010
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MOLECULES
CH3
Molecule is a configuration of atoms in precisely
defined ratio bonded together by ionic or
covalent forces. Molecular mass is the sum of
atomic masses multiplied by corresponding number
of atoms. Example MC6H66x126x178 g/mol
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BINARY COMPOUNDS
CH3

• Binary compound consists of n-atoms A and m-atoms
  B, formula AnBm.
• Binary compound is electrically neutral from
  outside, therefore n,m must be related by
  oxidation numbers of elements OA and OB
• n . OA m . OB 0
• Oxidation numbers are not unique for different
  elements (some elements have different oxidation
  numbers in different compounds), however there
  are some rules, related to corresponding columns
  in periodic table.
• Elements in 1.column have always OA 1 (alkali
  metals are donators of electron and become
  cations)
• Elements in 2.column have always OA 2
• Elements in 13.column have usually OA 3
  (example Al aluminium)
• Elements in 16.column have usually OB -2
  (nonmetals, example O,S)
• Elements in 17.column have OB -1 (halogens
  F,Cl,Br,I are acceptors of electron and become
  anions)

Example Fe2O3 Iron is in the column 8
(variable oxidation number, not known in
advance), however O has oxidation number -2,
therefore the oxidation number of iron must be 3
in this compound.
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BINARY COMP. COVALENT
CH3

• Nomenclature of binary compounds AmBn (both A,B
  are nonmetals)
• Binary NONMETALS with covalent bonds ALWAYS use
  PREFIXES (di-, tri-)
• Write more metallic element (with positive
  oxidation number) first.
• Examples
• SiC Silicon carbide (or monosilicon monocarbide)
• Evaluate oxidation number from electronegativities
  (look at the table) eSi1.7, eC2.5
  therefore carbon is stronger, attracts 4
  missing electrons and becomes negative with
  oxidation number OC-4, while OSi4 and balance
  is preserved -440 . Element with positive
  oxidation number is the first (CSi-wrong)
• CS2 Carbon disulfide (monocarbon disulfide)
• Electronegativities eS2.4, eC2.5
  Sulphur in column 16, therefore OS-2, OC4
  4-2x20
• N2O5 Dinitrogen pentoxide
• NO Nitrogen monoxide
• ClO2 Chlorine dioxide
• NO3 Nitrogen trioxide

• SF6

Sulfur hexafluoride

• SO2

Sulfur dioxide

• OF2

Oxygen difluoride
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BINARY COMPOUND IONIC
CH3

• Nomenclature of binary compounds AmBn (A-metal,
  B-nonmetal)
• Binary METALNONMETAL (ionic bonds) WITHOUT
  PREFIX, use ROMAN numerals for variable oxidation
  number of metal Fe2, Fe3, Cu2, Cu.
• Write always the metal first.
• Examples
• NaCl sodium chloride
• MgO magnesium oxide
• MgBr2 magnesium bromide (and not dibromide,
  oxidation number of Mg is always 2)
• Al2O3 aluminium oxide (without prefix, because
  oxidation numbers are unique)
• CuO copper(II) oxide (this is the case, when
  oxidation number of metal is variable and must be
  determined from oxidation number of oxygen 2,
  expressed as roman II)

• Cu2O

Copper(I) oxide

• Fe2O3

Iron(III) oxide

• CaCl2

Calcium chloride
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Polyatomic IONs
CH3

• Anions (negative electrical charge)
• F - fluoride
• Cl - chloride
• Br - bromide
• I - iodide
• CO3 - - carbonate (two negative charges)
• HCO3 - bicarbonate
• PO4 - - - phosphate (three negative charges)
• O2 - - peroxide
• OH - hydroxide
• CH3COO - acetate
• NO2- nitrite, NO3- nitrate (ion with less
  oxygens ends with ite, otherwise ate)
• SO3 - - sulfite, SO4 - - sulfate
• ClO hypo chlorite, ClO2 chlorite, ClO3 chlorate,
  ClO4 perchlorate
• Cations (positive electrical charge)
• NH4 amonium
• H3O hydronium

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Compounds with Polyatomic IONs
CH3

• Common (unsystematic) names used by chemists
  (derived from names of ions)
• Examples
• Na2SO4 sodium sulfate (more oxygens use ate,
  systematic name sodium tetraoxosulfate)
• Na2SO3 sodium sulfite (less oxygens use ite)
• NH4Br amonium bromide
• NaOH sodium hydroxide

• Ca(OH)2

Calcium hydroxide

• (NH4)2SO4

Ammonium sulfate (and not sulfite)

• H2CO3

Hydrogen carbonate

• Cu2CO3

Copper(I) carbonate

• NH4NO3

Ammonium nitrate
Potassium cyanide

• KCN

• Fe3(PO4)2

Iron(II) phosphate

• Al(NO3)3

Aluminium nitrate
Ammonium chloride

• NH4Cl

Calcium carbonate (limestone)

• CaCO3

Hydrogen nitrate (nitric acid)

• HNO3

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Inorganic ACIDS and salts
CH3

• Common (unsystematic) names used by chemists
  (derived from names of ions)
• Examples
• HCl hydrogen chloride hydrochlorid
  acid (when dissolved as electrolyte)
• HNO3 hydrogen nitrate nitric acid
  (more oxygens use ic)
• HNO2 hydrogen nitrite nitrous acid
  (less oxygens use ous)
• H2SO4 hydrogen sulfate sulfuric acid
• H2SO3 hydrogen sulfite sulfurous acid
  (less oxygens use ous)
• CaSO3 calcium sulfite
• CaSO4 calcium sulfate (salt produced by
  neutralization Ca(OH)2H2SO4?CaSO42H2O)

• H2CO3

Hydrogen carbonate carbonic acid

• HF

Hydro fluorid acid
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Scheme for naming ACIDS
CH3
Yes
Is there oxygen in anion? Hn anion
No
Anion name ends -ITE -ATE
HYDRO anion IC Example
HF hydro fluoric acid HBr hydro bromic
acid
NO2 nitrite SO3 sulfite
NO3 nitrate SO4 sulfate
anion IC Example
HNO3 nitric acid H2SO4 sulfuric acid
anion OUS Example
HNO2 nitrous acid H2SO3 sulfurous acid
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Lewis formula
CH3
Deeper insight into molecular structure is
yielded by the Lewis electron-dot formulas. Lewis
symbols consist of the symbol for the element and
one dot for each electron in the valence shell
(the symbol represents the kernel of
atomnucleuselectrons not taking part in
bonding). A dash is used to indicate a shared
pair of electrons instead of a colon (one dash
denotes a single bond, two dashes a double bond,
and three dashes a triple bond). water H2O
methane CH4 ethylene C2H4
benzene C6H6
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Lewis formula
CH3

• How to derive the Lewis formula, given a chemical
  formula.
• Draw a possible structure(s) of molecule (e.g.
  O-C-O, or C-O-O for CO2)
• Calculate total number of valence electrons
• Try to distribute these electrons so that all
  elements fill their valence shell (octet rule).
• Water methane CH4
  ethylene C2H4 benzene C6H6
• 628 el. 448 el.
  8412 el. 24630 el.

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Lewis formula of ions
CH3

• How to derive the Lewis formula, given a chemical
  formula and charge of ion.
• Draw a possible structure(s) of ion
• Calculate total number of valence electrons
  charge of ion
• Try to distribute these electrons so that all
  elements fill their valence shell (octet rule).
• Ammonium (NH4)
  Sulfate (SO4)2-
• (54) - 18 electrons
  (64x6) 232 electrons .

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Relax
CH3
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MIXTURES - concentrations
CH3
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MIXTURES - concentrations
CH3
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MASS BALANCING
CH3
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MASS BALANCING
CH3
Example burner (continuous system) f-fuel,
o-oxidiser, e-flue gas streams,
Mass flowrate kg/s. Streams are composed of
O2,N2,CO2,CO,CH4,H2O
Mass balance of mixture
Mass balances of individual components (chemical
compounds)
Mass balances of elements (C,H,O,N - four
equations)
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STOICHIOMETRY OF CHEMICAL REACTION
CH3
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Tutorial - Stoichiometry
CH3
My car has consumption 9 l/100 km (fueloctane).
How many kg of CO2 will be produced in my way
Praha-Nachod? Distance 290 km (use
www.mapy.cz). Octane CH3(CH2)6CH3 , density 703
kg/m3 (use www.wikipedia.com)
Answer 56.7 kg CO2
Remark gasoline is in fact a mixture of
hydrocarbons, including aromatic hydrocarbons
like benzene (C6H6) and toluene (C6H5CH3). Octane
is only one of many component in the mixture.
solution consumed Octane 2.9x9x0.70318.35kg mass
fraction of C in octane 8x12/(8x12626)0.842 b
urned C 18.35x0.84215.45 kg 12kgC corresponds to
44kgCO2. therefore 15.45/12x4456.7 kg CO2
Notice the fact that it was not necessary to know
the chemical reaction (oxidation of octane)!
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Tutorial - Stoichiometry
CH3
How many kg of air will be consumed on my way
Praha-Nachod (assuming ideal combustion of
octane)? Air Mixture of O2 (21 volum.), N2 (79)
Hint It is necessary to calculate mass fraction
of oxygen in air.
2C8H18 25O2 ? 16CO2 18H2O 228kg
800kg 704kg 324kg 18.35kg 64.4kg
56.7kg 26.1 kg
There was consumed 64.4kg of pure oxygen.
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Tutorial naming and formula
CH3

• SF6

Sulfur hexafluoride

• Fe2O3

Iron (III) oxide

• (NH4)2SO4

Ammonium sulfate (and not sulfite)

• Al(NO3)3

Aluminium nitrate

• HNO3

Nitric acid

• HNO2

Nitrous acid

• H2CO3

Carbonic acid

• H2SO3

Sulfurous acid

• H2SO4

Sulfuric acid

• CuI

Copper(I) iodide

• CaCO3

Calcium carbonate

• CaSO4

Calcium sulfate

• Na2SO3

Sodium sulfite
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Tutorial Lewis formula
CH3

• How to derive the Lewis formula, given a chemical
  formula and charge of ion.
• Draw a possible structure(s) of ion
• Calculate total number of valence electrons (
  charge of ion)
• Try to distribute these electrons so that all
  elements fill their valence shell (octet rule).
• CO2 CO
  N2

C?O
OCO