Pure Substances and Mixtures
 What is the difference between a pure substance and a
mixture?
Pure substance is made of one substance and a
mixture is a combination of two of more
substances
 What are the two types of mixtures?
Heterogeneous- made of two different phases of matter
Homogeneous- made of one phase of matter; solution
 Which type of mixture are these?
Homogeneous
Heterogeneous
The ATOM
Element
Symbol
Element
Element
Mass
Mass ## of
of pp++
Name
Name Number
Number
# of n0
# of e-
Cl-35
Chlorine
35
17
18
17
Mn-55
Mn-55
Manganese
55
25
30
25
K-42
K-42
Potassium
42
19
23
19
Si-26
Si-26
Silicon
26
14
12
14
Calculating Atomic Mass
 Calculate the atomic mass:
Atomic mass= (23.985)(0.7870)
(24.986)(0.1013)
+(25.983)(0.1117)
24.31 amu
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
•
•
•
•
•
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. 0.0003 has one.)
Zeros at the end of the number after a decimal
place are significant. (e.g. 123.00 g)
Zeros at the end of a number before a decimal
place are ambiguous (e.g. 10,300 g).
Periodic Table Groups
 Name special names for these sections of the table:
E
A
B
D
C
F
A: Alkali metals
B: Alkaline Earth metals
C: Transition metals
D: Halogens
E: Nobel Gases
F: Inner Transition metals
Metals, Non-metals, and Metalloids
 What are the properties of metals?
Malleable, Ductile, Lustrous,
Good Conductors
 What are the properties of non-metals?
Dull, Brittle, and Insulators
 What is a semiconductor?
Metalloid material that can
conduct electricity
Periodic Table Trends
 Put these elements in order of decreasing Atomic radius:
 Al, Ag, Au, Ba, Sr
Ba, Sr, Au, Ag, Al
 Put these ions in order of increasing Ionic Size:
 Br-, O2-, N3-, Cl-, F-
F-, O2-, N3-, Cl-, Br-
 Put these elements in order of decreasing
electronegativity:
 Br, Rb, B, Li, F
F, Br, B, Li, Rb
Types of Chemical Reactions
 What are the 5 types of chemical reactions?
1)
Synthesis
4)
Double
2)
Decomposition
Replacement
3)
Single
5)
Combustion
Replacement
 H2 + O2 
Synthesis
 H2O 
Decomposition
 Zn + H2SO4 
Single Replacement
 HgO 
Decomposition
 KBr +Cl2 
Single Replacement
 AgNO3 + NaCl 
Double Replacement
 Mg(OH)2 + H2SO3  Double Replacement
Dynamic Equilibrium
 Look at the following reaction at equilibrium:
H2(g) + I2(g) <===> 2HI (g)
 What will adding H2(g) do the concentration of HI(g)?
HI(g) will increase in concentration
 What will removing I2(g) do to the concentration of HI(g)?
HI(g) will decrease in concentration
Radioactive Decay
 What are the 3 types of radioactive decay?
 Which is most dangerous to living things?
Alpha, Beta, and Gamma decay
 What type of radioactive decay is this?
Beta decay
 What is missing from this equation?
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
y
0.5( )
Nt= 1.53mg x
Nt= 0.499
(13.0/8.04
0.5
)
Lewis Dot Structures
 Draw the Lewis Dot structure for the following:
Al, Cl, B, O, NaCl, O2
Compound Naming
 Name for following compounds:
1) MgO
2) AlS3
3) N2O5
4) Na3PO4
5) Mg(OH)2
6) (NH4)2 Cr2O7
7) K2SO3
8) CrPO4
9) Fe2 (SiO3)3
10) Hg(C2H3O2)2
1) Magnesium oxide
2)Aluminum sulfide
3)Dinitrogen Pentoxide
4)Sodium phosphate
5)Magnesium hydroxide
6)Ammonium dichromate
7)Potassium sulfite
8)Chromium (III) phosphate
9)Iron (III) silicate
10)Mercury (II) acetate
Compound Naming II
 Write the formula for following compounds:
1) Au(CN)3
Calcium hydrogen carbonate 2)Ca(HCO )
3 2
Strontium nitrate
3)Sr(NO3)2
Carbonic acid
4)H2CO3
Calcium chloride septahydrate 5)CaCl ∙ 7H O
2
2
Sulfurous acid
6)H2SO3
Lead (IV) phosphite
7)Pb3(PO3)4
Lithium chlorite
8)LiClO2
Magnesium hypochlorite
9)Mg(ClO)2
Beryllium perchlorate
10)Be(ClO4)2
1) Gold (III) cyanide
2)
3)
4)
5)
6)
7)
8)
9)
10)
Electron Configurations
 What are the principle quantum energy levels and
sublevels? How many orbitals in each sublevel?
n= 1, 2, 3, 4, 5, 6, 7
s= 1 orbitals
p= 3 orbitals
d= 5 orbitals
f= 7 orbitals
 Write the full electron configuration for Iodine:
1s2 2s22p6 3s23p6 4s23d104p6 5s24d105p5
 Write the abbreviate electron configuration for Ra+2:
[Rn]
Molecular Structures
 Name the molecular structure for the following and
list the number of lone pairs and bonds:
1)
CO2
1) 2, 0; Linear; 180
2) NH3
2)3, 1; Trigonal pyramidal; 107
3)6, 0; Octahedral; 90
3) SeF6
4)4, 0; Tetrahedral; 109.5
4) CH4
5)2, 2; Bent; 105
5) H2O
6)2, 1; Bent; 120
6) SO2
7)5, 0; Trigonal bypyrmidal; 90, 120
7) PCl5
8)3, 0; Trigonal planar; 120
8) SO3
9)3, 1; Trigonal pyramidal; 107
9) PCl3
Stoichiometry
 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)
3.62 mol N2H4
1 mol N2O4
2 mol N2H4
= 1.81 mol N2O4
 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.
Mol
K= 0.89
g/39
g =mol
0.02Cr
mol
K= 0.02
mol K/
0.02
= 1;KK
KCrO4;
Mol
Cr= 1.18
g/
520.02
g = 0.02
mol
Cr
Cr=
0.02
mol
Cr/
mol
Cr
=
1; Cr
Potassium chromate
Mol
O= 1.27
g = 0.08
mol
O O4
O= 0.08
molg/
O/160.02
mol Cr
= 4;
Stoichiometry
 How many atoms are in 90 L of O2 gas at STP?
90 L O2
1 mol O2
22.4 L O2
6.022 x 1023 atoms of O2
= 2.4 x 1024 atoms of O2
1 mol O2
 What is the empirical formula of the compound that is
42.10 % carbon, 5.26 % hydrogen, 24.56 % nitrogen, and
28.07 % oxygen? If molecular mass of the compound is
found to be 171.2 g/mol what is it's molecular formula?
C2NOH3 = 57 g
171.2 g / 57 g = 3
(C2NOH3) x 3 = C6N3O3H6