Chemical Formulas
I.
Ionic Substances –
A.
Profile
1.
Made of metal ( cation / +) and a nonmetal ( anion/ - )
2.
Form crystal lattices that are brittle, will cleave or break along crystal planes
3.
High melting points
4.
.
Dissolve in water to create ions which conduct electricity
a.k.a. salts
B.
1.
Writing formulas
Write the
symbols for the cation, then the anion
2.
Find the charges for each using the periodic table for the cations and your reference chart for the anions
Things to Note:
3.
The number of electrons lost must equal the number of electrons gained. Place subscripts next to the cation and anion which will make the total
number of electrons the same.
*Technique : The Switcheroo : Use the charge on the cation as the subscript for the anion and visa versa.
4.
Reduce the numbers if possible. Always use the lowest whole number ratios
C.
Naming Formulas
1.
Write the name
2.
3.
of the cation and the name of the anion.
If the anion is from the periodic table, change the ending to – ide
Use a Roman numeral to indicate the charge on transition metals, with multiple charges .
tables for examples. Use the reverse switcheroo to determine the charge if needed.
Refer to your agenda periodic
Polyatomic Diversity
Home base
ending
per + ate
1 more O
-ate
-----------------
-ite
1 less O
hypo + ite
2 less O
Any home base anion from your chart, your text, your homework, your ingredient labels or anywhere around the world, can be represented in all four ways by
adjusting the name or number of O in the formula !
3-2: Name the following substances.
1. FeSO3 :
iron II sulfite
2. Cu(NO3)2:
13. N2O4:
copper II nitrate
3. Hg2Cl2:
14. Rb3P
4. AgBr:
mercury I chloride
15. S8
5. KClO3:
silver bromide
Fe2O3
potassium16.chlorate
6. MgCO3:
17. (NH4)2SO3
7. BaO2:
magnesium carbonate
18. Ca(MnO4)2
8. KO2:
barium peroxide
19. PF5
9. SnO2:
potassium superoxide
20. LiH
10. Pb(OH)2: tin IV oxide
21. Ti(HPO4)2
11. Ni3(PO4)2:
12. CuCH3COO:
copper I acetate
dinitrogen tetra oxide
rubidium phosphide
sulfur molecule
iron III oxide
ammonium sulfite
calcium permanganate
phosphorus pentafluoride
lithium hydride
lead II hydroxide
nickel II phosphate
titanium IV mono hydrogen phosphate
3-3: Write formulas for the following substances.
1. vanadium V oxide
2. dihydrogen monoxide
V2O5
hydrogen carbonate
3. ammonium oxalate
H2O
oxide
4. polonium IV thiocyanate
(NH4)2C2O4
dihydrogen phosphate
5. tetraphosphorus decaoxide
Po (SCN)6
6. zinc hydroxide
7. potassium cyanide
P4O1
mercury I nitrate
0
8. cesium tartrate
Zn(OH)2
9. oxygen molecule
potassium hydrogen phthalate KCN
10. mercury II acetate
11. silver chromate
Cs2C4H4O6
O
2
Hg(C2H3O2)2
Ag2CrO4
12. tin II carbonate
13. sodium
14. manganese VII
15. copper II
16. francium dichromate
17. calcium carbide
18.
19. cerium IV benzoate
20.
II.
Molecular Substances –
A.
Profile
1.
Made of nonmetals only ( no charges!)
2.
Found as solids, liquids or gases ( no crystal lattices)
3.
Low melting points
4.
Do not dissolve in water or conduct electricity
B.
Writing formulas
1.
Write the symbols for the elements present in the order they appear.
2.
Use subscripts to indicate the number
a.
Prefixes
1-mono
7-hepta
2-di
8-octa
3.
Do not reduce the numbers for the subscripts.
9-nona
3-tri
10-deca
of atoms of each element present as indicated by the prefixes in the name
4-tetra
11-undeca
5-penta 6-hexa
12-dodeca
These represent the minimum number of atoms needed for the substance in question.
C.
Naming formulas
1.
Write the name
2.
Change the ending of the last
3.
Use the prefixes to indicate the number
4.
Do not use mono on the first element
of each of the elements in the compound in the order they appear.
element to -ide
of atoms present.
If there is an o vowel repeated then only include it once
III.
Acidic Substances –
A.
1.
Profile
Made of mostly nonmetals, hydrogen is always present and usually is at the beginning or end of the formula
2.
Dissolves in water to produce H+ ions and anions
3.
Covalently bonded polyatomic ions, ionic bonds with H
4.
Named as ionic substances with a twist
Anion ending
Acid change (The twist)
-ate
-ic + acid
-ite
-ous + acid
-ide
Hydro + ic + acid
The acid phrase that pays: Say it with me now!
ate to ic, ite to ous, ide to hydro,ic acid. Again!
IV . Organic Substances
A.
Profile
1.
Always contain carbon and hydrogen, may also include other elements
2.
Covalently bonded chains, rings or small molecules
3.
Classified according to # or carbons, bond type and/or functional groups attached
a.
Prefixes = # of carbons
meth = 1 eth = 2 prop = 3
hex = 6 hept = 7 oct = 8
b.
i.
but = 4 pent = 5
non = 9 dec = 10
alkanes : simplest organic compounds – only single bonds
Cn H2n+2
ii.
–ane ending
c.
i.
alkene : 1 or more double bond in structure
Cn H2n( only works for one double bond)
ii.
–ene ending
d.
alkyne : 1 or more triple bonds in
structure
i.
ii.
Cn H2n-2
–yne ending
i.
ii.
iii.
iv.
e.
alcohol : hydroxide group attached somewhere
follows pattern for alk designation
anol ending – single bonds
enol ending – double bonds
ynol ending – triple bonds
***Identify substituents attached to the molecule by location, quantity and alphabetically by name. ( These
changes will take place at the beginning of the name/formula
Chains of one or more carbon ( methyl,ethyl,propyl,butyl,pentyl&..)
Halogens ( chloro,bromo,iodo,fluoro)
What if…….there is a ring ?
Cyclo should preceed the name
What if there are double, triple bonds ?
Identify which carbon they are on, by counting from the end closest to the
substituent.
What if there are multiple double or triple bonds?
Identify which carbon they are on by counting from the end closest to the
first one and keep numbering from then on.
What if there are other atoms attached and multiple bonds?
Number the carbons based on the location of the multiple bond and use those numbers to identify the
locations of the other atoms attached.
What if there are attachments and more than one multiple bond?
Number the carbons based on the location of the first multiple bond and indicate the attachments first, then
the location of the multiple bonds by number and with a prefix tucked into the final part of the name.