Transcript Slide 1
By John Weide with modifications by Ken Costello
Compounds are two or more elements that are held together by opposite charge attraction.
12 (+) 10 (-) +2 Charge Magnesium-12 Oxygen-8 8 (+) 10 (-) -2 Charge
Metal Non-metal
Metals combine with non-metals Metals loose electrons to non-metals They then attract because their charges will be opposite.
Most of the negative ions have a set negative charge
-3 -2 -1
+1 +2 +1 +2 +3 -3 -2 -1
POLYATOMIC IONS (charged building blocks) Polyatomic ions are mostly made of two non-metals.
Ions with -1 charge perbromate BrO 4 -1 bromate BrO 3 -1 bromite BrO 2 -1 hypobromite BrO -1 perchlorate ClO 4 -1 chlorate ClO 3 -1 chlorite ClO 2 -1 hypochlorite ClO -1 periodate IO 4 -1 iodate IO 3 -1 iodite IO 2 -1 hypoiodite IO -1 nitrate nitrite hydroxide cyanide NO 3 -1 NO 2 -1 OH CN -1 -1 acetate C 2 H 3 O 2 -1 Permanganate MnO 4 -1 bicarbonate HCO 3 -1 Ions with a -2 Charge carbonate CO 3 -2 sulfate SO 4 -2 sulfite SO 3 -2 chromate CrO 4 -2 dichromate Cr 2 O 7 -2 oxalate C 2 O 4 -2 Ions with a -3 Charge phosphate PO 4 -3 phosphite PO 3 -3 arsenate AsO 4 -3 Ions with +1 charge ammonium ion NH 4 +1
These polyatomic ions match the charge of the single element Ions with -1 charge perbromate BrO 4 -1 bromate BrO 3 -1 bromite BrO 2 -1 hypobromite BrO -1 perchlorate ClO 4 -1 chlorate ClO 3 -1 chlorite ClO 2 -1 hypochlorite ClO -1 periodate IO 4 -1 iodate IO 3 -1 iodite IO 2 -1 hypoiodite IO -1
-1
These polyatomic ions match the charge of the single element Ions with a -2 Charge sulfate SO 4 -2 sulfite SO 3 -2 -3 -2 Ions with a -3 Charge phosphate PO 4 -3 phosphite PO 3 -3
Elements with Fixed Oxidation Numbers +1+2
1A H 2A Li Be Na Mg Click on element to see its oxidation number(s)
+3 -4-3-2-1
3A 4A 5A 6A
0
7A 8A H He B C N O F Ne Al Si P S Cl Ar K Ca Rb Sr Ce Ba Fr Ra Sc Ti V Cr Mn Fe Y Zr Nb Mo Tc Ru Co Ni Cu Zn Rh Pd Ag Cd La Hf Ta W Re Os Ir Pt Au Hg Ac Rf Db Sg Rh Hs Mt Ga Ge As Se Br Kr In Sn Sb Te I Xe Tl Pb Bi Po At Rn Ce Pr Th Pa Nd Pm Sm Eu Gd Tb Dy Ho Er Tm Yb Lu U Np Pu Am Cm Bk Cf Es Fm Md No Lr Next Slide
Examples #1- Formulas to Names
1. Write the names of the ions
Cu SO 3
2. Determine the charge of the positive ion Cu
SO 3 -2 = 0 You must know the charge on the sulfite ion is -2 X + ( - 2) X = 0 +2 +2 = +2
copper
(II)
sulfite
Final Name
Examples #2- Formulas to Names
1. Write the names of the ions
K MnO 4 I’m a polyatomic ion
potassium permanganate
Final Name If the positive ion has a fixed charge, you are finished.
Examples #3- Formulas to Names
1. Write the names of the ions 2. Determine the charge of the positive ion
NH 4 NO 3 I’m a polyatomic ion
ammonium nitrate
Final Name If the positive ion has a fixed charge, you are finished.
Examples #4- Formulas to Names
1. Write the names of the ions 2. Determine the charge of the positive ion
X = +2 X + 2 ( -1 ) = 0
Sn
x ( F -1 ) 2 Sn F 2 = 0
tin
(II)
fluoride
Final Name
Examples #5- Formulas to Names
1. Write the names of the ions 2. Determine the charge of the positive ion
barium
Ba (ClO 4 ) 2 I’m a polyatomic ion
perchlorate
Examples #6- Formulas to Names
1. Write the names of the ions 2. Determine the charge of the positive ion
X = +1 2X + ( -2 ) = 0 2Cu x (S) -2 = 0 Cu 2 S I’m not a polyatomic ion
copper
(I)
sulfide
Final Name
Examples #7- Formulas to Names
1. Write the names of the ions 2. Determine the charge of the positive ion
X = +1 2X + ( -2 ) = 0 2 ( Na x ) (Cr 2 O 7 ) -2 Na 2 Cr 2 O 7 = 0 I’m a polyatomic ion
sodium
(I)
dichromate
Final Name charge, it is not shown
Examples #10- Formulas to Names
1. Write the names of the ions 2. Determine the charge of the positive ion
Li CN I’m a polyatomic ion
lithium cyanide
Writing Ionic Formulas
• It is easier to write the formula of an ionic compound from its name than the reverse. • The oxidation number of the negative ion must be memorized in all cases. Refer to the table of polyatomic ions.
Practice Problems
By now you should have an idea of what is expected when naming covalent binary compounds using prefixes.
In order to master this naming system you need to practice until you feel proficient in naming compounds using prefixes.
Practice Problem #1
Fe (NO 3 ) 3
Choose the correct name for the compound 1. Iron trinitrate 2. iron(I) nitrate 3. iron(III) nitrite 4. iron(III) nitrate 5. none of the above
Practice Problem #2
sodium chlorite
Choose the correct formula for the compound
1. NaCl 2. NaClO 3. NaClO 2 4. Na(ClO) 2 5. none of the above
POLYATOMIC IONS
Ions with -1 charge perbromate BrO 4 -1 bromate BrO 3 -1 bromite BrO 2 -1 hypobromite BrO -1 perchlorate ClO 4 -1 chlorate ClO 3 -1 chlorite ClO 2 -1 hypochlorite ClO -1 periodate IO 4 -1 iodate IO 3 -1 iodite IO 2 -1 hypoiodite IO -1 nitrate NO 3 -1 nitrite NO 2 -1 hydroxide OH -1 cyanide CN -1 thiocyanate SCN -1 acetate C 2 H 3 O 2 -1 Permanganate MnO 4 -1 bicarbonate HCO 3 -1 Ions with a -2 Charge carbonate CO 3 -2 phthalate C 8 H 4 O 4 -2 sulfate SO 4 -2 sulfite SO 3 -2 chromate CrO 4 -2 dichromate Cr 2 O 7 -2 oxalate C 2 O 4 -2 peroxide O 2 -2 Ions with a -3 Charge phosphate PO 4 -3 phosphite PO 3 -3 arsenate AsO 4 -3 Ions with +1 charge ammonium ion NH 4 +1
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Oxidation Numbers
(most common)
1A H 2A Li Be Na Mg K Ca Rb Sr Ce Ba Fr Ra
+1 +2 +2 +3
Click on element to see its oxidation number(s) Sc Ti V Cr Mn Fe Y Zr Nb Mo Tc Ru Co Ni Cu Zn Rh Pd Ag Cd La Hf Ta W Re Os Ir Pt Au Hg Ac Rf Db Sg Rh Hs Mt 3A B
+2 +4
4A 5A 6A 7A 8A H He C N O F Ne Al Si P S Cl Ar Ga Ge As Se Br Kr In Sn Sb Te I Xe Tl Pb Bi Po At Rn
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Ce Pr Th Pa Nd Pm Sm Eu Gd Tb U Np Pu Am Cm Bk Dy Ho Er Tm Yb Lu Cf Es Fm Md No Lr