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Chemical Nomenclature

Chemical Nomenclature. Ionic Compounds often a metal + nonmetal anion (nonmetal), add “ide” to element name. barium chloride. BaCl 2. Known as a subscript. K 2 O. potassium oxide. Mg(OH) 2. magnesium hydroxide. KNO 3. potassium nitrate. 11 protons 11 electrons. 11 protons

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Chemical Nomenclature

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  1. Chemical Nomenclature • Ionic Compounds • often a metal + nonmetal • anion (nonmetal), add “ide” to element name barium chloride BaCl2 Known as a subscript K2O potassium oxide Mg(OH)2 magnesium hydroxide KNO3 potassium nitrate

  2. 11 protons 11 electrons 11 protons 10 electrons Na+ Na 17 protons 18 electrons 17 protons 17 electrons Cl- Cl An ion is an atom, or group of atoms, that has a net positive or negative charge. cation – ion with a positive charge If a neutral atom loses one or more electrons it becomes a cation. anion – ion with a negative charge If a neutral atom gains one or more electrons it becomes an anion.

  3. Forming Cations & Anions A CATION forms when an atom loses one or more electrons. An ANION forms when an atom gains one or more electrons F + e- --> F- Mg --> Mg2+ + 2 e-

  4. How many protons and electrons are in ? How many protons and electrons are in ? 27 78 3+ 2- Al Se 13 34 Do You Understand Ions? 13 protons, 10 (13 – 3) electrons 34 protons, 36 (34 + 2) electrons

  5. A monatomic ion contains only one atom Na+, Cl-, Ca2+, O2-, Al3+, N3- A polyatomic ion contains more than one atom OH-, CN-, NH4+, NO3-

  6. Compound Names and Formulas A. Naming ionic compounds 1. Ionic - transfer of electrons - causing one element to become a positive ion (cation) and one element to become a negative ion (anion) 2. the positive ion always come first NaCl is never written as ClNa 3. The name is derived from the ions that make it up a. naming binary ionic compounds - two elements

  7. i. the positive ion is simply the name ion the element ii. Na+ is sodium Ba++ is Barium b. the negative ion’s ending is changed to ide i. chlorine - Cl is changed to Cl- - chloride c. some polyatomic ions are name according to their oxygen content Sulfate and sulfite SO4-- and SO3--

  8. d. Some cations must show their charge Fe++ is known as the Iron II ion Fe+++is known as the Iron III ion e. when writing chemical formulas from their names - the number of positive ions must equal the number of negative ions Sodium fluoride Na+F - - these charges are balanced

  9. Calcium chloride Ca++Cl- - these charges are not balanced so we must adjust the subscripts so the number of + equals the number of - Ca++Cl2- Remember - Charges must be balanced - so you must have 2 -1’s to balance the +2 Coefficient subscript 2NH4+ + CO3-2 ==> (NH4+ ) 2 CO3-2 Ammonium carbonate carbonate Ammonium Use coefficients to balance the total number of atoms - Always balance charges first using subscripts

  10. +1 with -1 Ammonium with acetate NH4+ + C2H3O2- ==> NH4+ C2H3O2- Ammonium acetate Ammonium Acetate

  11. Cu+1 + C2H3O2- => Cu+1C2H3O2- copper (I) acetate copper (I) acetate

  12. +1 with -2 There is an issue CO3 -- NH4+ 2 NH4+ + ( ) CO3-- 2 Ammonium carbonate Carbonate Ammonium You must make the charges equal now you must balance it according to the conservation of mass

  13. +1 with -3 You must always have the charges equal - so must have 3 +1 with the -3 3NH4+ + PO4 -3 ==> (NH4+)3PO4-3 Ammonium phosphate phosphate Ammonium +2 with -1 You must always have the charges equal - so must have 2 -1’s to equal the +2 Ca+2 + 2C2H3O2 -1 ===> Ca+2(C2H3O2-)2 acetate Calcium acetate Calcium

  14. +2 with -2 Since the charges are equal - you simply put them together Ca + 2 + CO3-2 ===> CaCO3 Calcium Carbonate Calcium Carbonate +2 with -3 Since the charges are not equal - you must find the LCD for 2 and 3 which is 6 so 3Ca + 2 + 2 PO4 -3 ==> Ca+23(PO4 -3 )2 Calcium Phosphate Calcium Phosphate

  15. +3 with -1 Al+3 + 3 C2H3O2- Al+3(C2H3O2-)3 Aluminum Acetate Aluminum Acetate

  16. +3 with -2 2Al+3 + 3CO3--  Al+32 (CO3--)3 Aluminum Carbonate Aluminum Carbonate

  17. +3 with -3 Al +++ + PO4---  Al+++PO4 --- Aluminum Phosphate Aluminum Phosphate

  18. molecular empirical H2O A molecular formula shows the exact number of atoms of each element in the smallest unit of a substance An empirical formula shows the simplest whole-number ratio of the atoms in a substance H2O CH2O C6H12O6 O3 O N2H4 NH2

  19. Molecular compounds • nonmetals or nonmetals + metalloids • common names • H2O, NH3, CH4, C60 • element further left in periodic table is 1st • element closest to bottom of group is 1st • if more than one compound can be formed from the same elements, use prefixes to indicate number of each kind of atom • last element ends in ide

  20. TOXIC! Laughing Gas Molecular Compounds HI hydrogen iodide NF3 nitrogen trifluoride SO2 sulfur dioxide N2Cl4 dinitrogen tetrachloride NO2 nitrogen dioxide N2O dinitrogen monoxide

  21. Mixed Practice • N2O • K2S • Cu(NO3)2 • Cl2O7 • Cr2(SO4)3 • Fe2(SO3)3 • CaO • BaCO3 • ICl • Dinitrogen monoxide • Potassium sulfide • Copper (II) nitrate • Dichlorine heptoxide • Chromium (III) sulfate • Iron(III) sulfite • Calcium oxide • Barium carbonate • Iodine monochloride

  22. Mixed Practice • Barium iodide • Tetraphosphorus trisulfide • Calcium hydroxide • Iron (II) carbonate • Sodium dichromate • Diiodine pentoxide • Cupric perchlorate • Carbon disulfide • Diboron tetrachloride • BaI2 • P4S3 • Ca(OH)2 • FeCO3 • Na2Cr2O7 • I2O5 • Cu(ClO4)2 • CS2 • B2Cl4

  23. Examples of Older Names of Cations formed from Transition Metals(memorize these!!) From Zumdahl

  24. nitric acid HNO3 carbonic acid H2CO3 H2SO4 sulfuric acid An acid can be defined as a substance that yields hydrogen ions (H+) when dissolved in water. • HCl • Pure substance, hydrogen chloride • Dissolved in water (H+ Cl-), hydrochloric acid An oxoacid is an acid that contains hydrogen, oxygen, and another element. HNO3

  25. Transition metal ionic compounds • indicate charge on metal with Roman numerals iron(II) chloride FeCl2 2 Cl- -2 so Fe is +2 FeCl3 3 Cl- -3 so Fe is +3 iron(III) chloride Cr2S3 3 S-2 -6 so Cr is +3 (6/2) chromium(III) sulfide

  26. Oxidation and reduction 1. Oxidation and reduction (redox reactions) A. Oxidation - loss of electrons B. Reduction - gain of electrons Oxidation-reduction reactions MUST happen at the same time

  27. C. Oxidation numbers - number of electrons gained, lost or shared 1. how to assign oxidation numbers a. free elements are assigned an oxidation number of zero i. free element - any un- combined element - this includes the 7 diatomics H2, N2, O2, F2, Cl2, Br2, I2 These 7 elements must be together if they are alone

  28. b. mono atomic ion's charge equals their oxidation number i. Na+1= +1 ii. S-2 = -2 c. hydrogen's oxidation is =1 d. oxygen's oxidation number is -2 except in peroxides. In peroxides, the oxidation is -1

  29. e. the sum of the oxidation numbers of a compound must add up to be zero f. the sum of the oxidation numbers of a polyatomic ion must add up to equal its charge

  30. The oxidation number of hydrogen is +1except when it is bonded to metals in binary compounds. In these cases, its oxidation number is –1. Oxidation numbers of all the elements in HCO3- ? • Group IA metals are +1, IIA metals are +2 and fluorine is always –1. 6. The sum of the oxidation numbers of all the atoms in a molecule or ion is equal to the charge on the molecule or ion.

  31. +1 -2 HCO3- +1 ? +4 -6 = -1 H = +1 O = -2 C = +4

  32. Oxidation number The charge the atom would have in a molecule (or an ionic compound) if electrons were completely transferred. • Free elements (uncombined state) have an oxidation number of zero. Na, Be, K, Pb, H2, O2, P4 = 0 • In monatomic ions, the oxidation number is equal to the charge on the ion. Li+, Li = +1; Fe3+, Fe = +3; O2-, O = -2 • The oxidation number of oxygen isusually–2. In H2O2 and O22- it is –1.

  33. Try some • find the oxidation numbers for each element

  34. 2 x +3 = +6 1 x +2 = +2 1 x +2 = +2 3 x -2 = -6 2 x -1 = -2 1 x -2 = -2 Formula of Ionic Compounds Al2O3 Al3+ O2- CaBr2 Ca2+ Br- Na2CO3 Na+ CO32-

  35. NH4+Br- Ca+2Cl-2 Na+C2H3O2- Cu+2SO4- K+HCO3- Ba+2(NO3-)2

  36. Zn+2S-2 Li+3PO4-3 Al+3(HSO4-)3 Fe+3 2O-2 3 Zn+2CO3-2 H+CN-

  37. Ag+ 2 Cr2O7 -2 Fe+3PO3-3 H2+ O2-2 Ca+2 HPO4-2 Cu+NO2- Cu+2 (NO2- )2

  38. Hg+2C2O4-2 Cr+3(OH- )3

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