1. Chemical Names and Formulas
Chapter 7

2. Chemical Formulas Chemical Formulas – number of each kind of atom
Ex. C8H18 , Al2(SO4)3

3. Memorize the charges of common monatomic ions using periodic table
Grp 1 elements +1 charge
Grp charge
Grp charge
Grp or +4 charge
Grp charge
Grp charge
Grp charge
Grp charge

4. Grp 3 to Grp 12 Transition Metals have varying positive charge.
These 3 ions do not vary in charge:
Ag+1, Cd+2, Zn+2
H+1 OR H-1

5. Naming Monatomic Ions
Positive Ions – use element name and add word ion
Ex. K+1 potassium ion
Ions with varying positive charge have a roman number after the name to indicate the charge of the ion
Ex. Fe+2 iron(II) ion OR Fe+3 iron(III) ion
Pb+2 lead(II) ion OR Pb+4 lead(IV) ion

6. Negative Ions
Negative Ions – use root name (drop last syllable) + -ide ion
Examples:
F-1 fluoride ion
Note: H-1 hydride ion O-2 oxide ion

7. Binary Cmpds
Binary Cmpds – cmpds with only two different elements

8. Writing Ionic Cmpds Steps:
Write symbol and charge of positive ions first.
Write symbol and charge of negative ion next.
Use subscripts if more than one ion is needed to make the total charge of the cmpd zero.

9. Examples Write formula for each cmpd: Aluminum oxide Calcium chloride
Potassium sulfide
Gold (IV) oxide
Prac. P207 and p209

10. Polyatomic Cmpds
Cmpds with polyatomic ions – use parentheses when more than one set of polyatomic ion is needed.
Examples
Tin(IV) sulfate
Calcium chlorate
Magnesium phosphate
Prac p211

11. Naming Ionic Cmpds Name cation, roman numeral, name anion (if needed)
Examples: Name
LiH
Na2SO4
MgCl2
CuCl2
Al2(SO4)3

12. Binary Molecular Cmpd.
Naming Binary Molecular Cmpd – only 2 elements in formula
Memorize the Greek prefixes for one to ten p212
Mono, di, tri, tetra, penta, hexa, hepta, octa, nona, deca

13. Molecular Cmpds.
Less electronegative element (more metallic first), and prefix to element to show number of atoms. Omit mono- for the first element.
Add prefix to root name of second element and add –ide ending.

14. Examples: Name
P4O10
N2O NO
NO2
N2O3
N2O4
N2O5
Prac p213

15. Covalent Network Cmpds
Atoms covalently bonded to its neighbors in a 3D network
Ex. SiC Illustrate

16. Acids
Acid – compounds with the hydrogen ion, H+1 , first in the formula

17. Hydrogen Anion Acid Name
-ate ic acid
-ite ous acid
-ide hydro ic acid
Ex. Hydrogen sulfate ________
hydrogen sulfite ________
hydrogen sulfide ________
(note: ur added in for S and added in for P)
Section Review p215

18. Using Chemical Formulas
Formula mass – sum of all masses of atoms in formula
Ex: formula mass of:
a. Fe
b. O2
c. H2O
d. C12H22O11
Practice p222

19. Molar Mass Molar Mass – mass in grams of one mole of a substance
Ex. Determine the molar mass of:
a. Fe
b. O2
c. H2O
d. C12H22O11
Practice p223

20. Formula Mass Vs. Molar Mass
Note: The only difference between formula mass and molar mass is the unit of amu and grams.

21. Mass to Moles Problem: Convert 2.34 X103 g of carbon to moles.
Convert 14.6 g of H2O to moles.
Prac. P226 #1

22. Mass to Number of Particles
Problem:
Convert X10-2 moles of carbon to atoms.
Change moles of water to molecules.
How many formula units is X10-3 moles of NaCl?

23. Mass to Number of Particles
Problems:
Convert a 14.3 g carbon, charcoal briquette, to atoms of C.
How many molecules of C13H18O2, ibuprofen, is in the bottle of g?

24. How much of table salt must be measured out to give 4
How much of table salt must be measured out to give 4.82 X1025 formula units of NaCl?
Prac p226 #2,3

25. Percent Composition
Percent Composition – percentage by mass of each element in the cmpd
From sample amts:
Mass of element in sample X 100=% E in cmdp
mass of sample
Ex:

26. From formula: Mass of E in 1 mol of cmpd X 100=% E in cmdp
molar mass of cmpd
Prac. Find the % composition of Cu2S.
Prac p228

27. Formulas
Empirical Formula – smallest whole number ratio of atoms in a compd.
Ex. HCl, H2O
Molecular Formula – actual formula of a molecule of compd – some multiple of the empirical formula
Ex. HCl, C2H4

28. Determine which is empirical and molecular formulas:
P2O5
NH3
C6H6
Ca(OH)2

29. Determining Empirical Formulas from Quantitative Analysis:
Convert % info to grams.
Convert grams to moles of element
Get whole number ratios by dividing by smallest # of moles.

30. Ex.
Find the empirical formula of a compd with 32.38% Na, 22.65% S, and 44.99% O.
Prac p231

31. Molecular Formula Calculation of Molecular Formula: x(EF) = MF
MF mass = x
EF mass
Problem must provide the molar mass of the compd from experimental data.

32. Ex.
A compd of phosphorus and oxygen has an empirical formula of P2O5. The molar mass is determined to be g. What is the molecular formula?
Prac p233 and section review p233