1. Chem Final Review

2. Pure Substances and Mixtures
What is the difference between a pure substance and a mixture?
What are the two types of mixtures?
Which type of mixture are these?
Pure substance is made of one substance and a mixture is a combination of two of more substances
Heterogeneous- made of two different phases of matter
Homogeneous- made of one phase of matter; solution
Homogeneous
Heterogeneous

3. The ATOM Element Symbol Element Name Mass Number # of p+ # of n0
# of e-
Cl-35
Mn-55
K-42
Si-26
Element Symbol
Element Name
Mass Number
# of p+
# of n0
# of e-
Cl-35
Chlorine 35 17 18
Mn-55
Manganese 55 25 30
K-42
Potassium 42 19 23
Si-26
Silicon 26 14 12

4. Calculating Atomic Mass
Calculate the atomic mass:
Atomic mass= (23.985)(0.7870)
(24.986)(0.1013)
+(25.983)(0.1117)
24.31 amu

5. Significant Figures (sig-figs)
The number of digits reported in a measurement reflect the accuracy of the measurement and the precision of the measuring device.
Report the fewest significant figures
Fewest number for multiplication and division
Fewest decimal places for addition and subtraction

6. Significant Figures (sig-figs)
Non-zero numbers (e.g. 1, 2, 3…9) are significant.
Zeros between non-zero numbers are always significant. (e.g. 204 ml) (the sandwich rule)
Zeros before the first non-zero digit are not significant. (e.g has one.)
Zeros at the end of the number after a decimal place are significant. (e.g g)
Zeros at the end of a number before a decimal place are ambiguous (e.g. 10,300 g).

7. Periodic Table Groups A: Alkali metals E: Nobel Gases
Name special names for these sections of the table: E A B D C F
A: Alkali metals
E: Nobel Gases
B: Alkaline Earth metals
F: Inner Transition metals
C: Transition metals
D: Halogens

8. Metals, Non-metals, and Metalloids
What are the properties of metals?
What are the properties of non-metals?
What is a semiconductor?
Malleable, Ductile, Lustrous, Good Conductors
Dull, Brittle, and Insulators
Metalloid material that can conduct electricity

9. Periodic Table Trends F-, O2-, N3-, Cl-, Br- F, Br, B, Li, Rb
Put these elements in order of decreasing Atomic radius:
Al, Ag, Au, Ba, Sr
Put these ions in order of increasing Ionic Size:
Br-, O2-, N3-, Cl-, F-
Put these elements in order of decreasing electronegativity:
Br, Rb, B, Li, F
Ba, Sr, Au, Ag, Al
F-, O2-, N3-, Cl-, Br-
F, Br, B, Li, Rb

10. Types of Chemical Reactions
What are the 5 types of chemical reactions?
Synthesis
Double Replacement
Decomposition
Single Replacement
Combustion
H2 + O2 ®
H2O ®
Zn + H2SO4 ®
HgO ®
KBr +Cl2 ®
AgNO3 + NaCl ®
Mg(OH)2 + H2SO3 ®
Synthesis
Decomposition
Single Replacement
Double Replacement

11. Dynamic Equilibrium HI(g) will decrease in concentration
Look at the following reaction at equilibrium:
H2(g) + I2(g) <===> 2HI (g)
What will adding H2(g) do the concentration of HI(g)?
What will removing I2(g) do to the concentration of HI(g)?
HI(g) will increase in concentration
HI(g) will decrease in concentration

12. Radioactive Decay Alpha, Beta, and Gamma decay Beta decay
What are the 3 types of radioactive decay?
Which is most dangerous to living things?
What type of radioactive decay is this?
What is missing from this equation?
Alpha, Beta, and Gamma decay
Beta decay

13. Calculating Half-Life
131I has a half-life of 8.04 days. Assuming you start with a 1.53 mg sample of 131I, how many mg will remain after 13.0 days __________ ?
Nt = N0 x 0.5(y)
Nt= 1.53mg x 0.5(13.0/8.04)
Nt= 0.499

14. Lewis Dot Structures
Draw the Lewis Dot structure for the following: Al, Cl, B, O, NaCl, O2

15. Compound Naming Magnesium oxide Aluminum sulfide Dinitrogen Pentoxide
Name for following compounds:
MgO
AlS3
N2O5
Na3PO4
Mg(OH)2
(NH4)2 Cr2O7
K2SO3
CrPO4
Fe2 (SiO3)3
Hg(C2H3O2)2
Magnesium oxide
Aluminum sulfide
Dinitrogen Pentoxide
Sodium phosphate
Magnesium hydroxide
Ammonium dichromate
Potassium sulfite
Chromium (III) phosphate
Iron (III) silicate
Mercury (II) acetate

16. Compound Naming II Au(CN)3 Ca(HCO3)2 Sr(NO3)2 H2CO3 CaCl2 ∙ 7H2O H2SO3
Write the formula for following compounds:
Gold (III) cyanide
Calcium hydrogen carbonate
Strontium nitrate
Carbonic acid
Calcium chloride septahydrate
Sulfurous acid
Lead (IV) phosphite
Lithium chlorite
Magnesium hypochlorite
Beryllium perchlorate
Au(CN)3
Ca(HCO3)2
Sr(NO3)2
H2CO3
CaCl2 ∙ 7H2O
H2SO3
Pb3(PO3)4
LiClO2
Mg(ClO)2
Be(ClO4)2

17. Electron Configurations
What are the principle quantum energy levels and sublevels? How many orbitals in each sublevel?
Write the full electron configuration for Iodine:
Write the abbreviate electron configuration for Ra+2:
n= 1, 2, 3, 4, 5, 6, 7
s= 1 orbitals p= 3 orbitals
d= 5 orbitals f= 7 orbitals
1s2 2s22p6 3s23p6 4s23d104p6 5s24d105p5
[Rn]

18. Molecular Structures 2, 0; Linear; 180 3, 1; Trigonal pyramidal; 107
Name the molecular structure for the following and list the number of lone pairs and bonds:
CO2
NH3
SeF6
CH4
H2O
SO2
PCl5
SO3
PCl3
2, 0; Linear; 180
3, 1; Trigonal pyramidal; 107
6, 0; Octahedral; 90
4, 0; Tetrahedral; 109.5
2, 2; Bent; 105
2, 1; Bent; 120
5, 0; Trigonal bypyrmidal; 90, 120
3, 0; Trigonal planar; 120

19. Stoichiometry = 1.81 mol N2O4 Mol K= 0.89 g/39 g = 0.02 mol K
Determine the number of moles of N2O4 needed to react completely with 3.62 mol of N2H4for the reaction
2 N2H4(l) + N2O4 (l) → 3 N2(g) + 4 H2O(l)
A sample of a substance is determined to be composed of 0.89 grams of potassium, 1.18 grams of chromium, and 1.27 grams of oxygen. Calculate the empirical formula of this substance. 
3.62 mol N2H4
1 mol N2O4
= 1.81 mol N2O4
2 mol N2H4
K= 0.02 mol K/ 0.02 mol Cr = 1; K
Cr= 0.02 mol Cr/ 0.02 mol Cr = 1; Cr
O= 0.08 mol O/ 0.02 mol Cr = 4; O4
Mol K= 0.89 g/39 g = 0.02 mol K
Mol Cr= 1.18 g/ 52 g = 0.02 mol Cr
Mol O= 1.27 g/ 16 g = 0.08 mol O
KCrO4;
Potassium chromate

20. Stoichiometry C2NOH3 = 57 g 171.2 g / 57 g = 3 (C2NOH3) x 3 = C6N3O3H6
How many atoms are in 90 L of O2 gas at STP?
 What is the empirical formula of the compound that is % carbon, 5.26 % hydrogen, % nitrogen, and % oxygen? If molecular mass of the compound is found to be g/mol what is it's molecular formula? 
90 L O2
1 mol O2
6.022 x 1023 atoms of O2
= 2.4 x 1024 atoms of O2
22.4 L O2
1 mol O2
C2NOH3 = 57 g
171.2 g / 57 g = 3
(C2NOH3) x 3 = C6N3O3H6