CHAPTER ONE
The Foundations of Chemistry
RECALL!!!
Elements:
Can not be broken down by
chemical reactions
Pure Substances
Compounds: Can be broken down ONLY
by chemical reactions
Matter
Homogeneous: Constant composition
throughout
Mixtures
Can be separated by
physical processes
Heterogeneous: Variable composition
throughout
2
States of Matter
3
E
D
B
C
A
4
States of Matter
5
Chemical and Physical Properties

Chemical Properties - chemical changes



rusting or oxidation
chemical reactions
Physical Properties - physical changes


changes of state
density, color, solubility
6
Question 1. Classify as mixtures (homogeneous or
heterogeneous), compounds (ionic or molecular), or elements
(monoatomic or molecular).
Classification
C2H5OH
Cl2
Cu
bronze
5% AgNO3
solution
C6H12O6
PbCl2 precipitate
Zn
Ba3(PO4)2
0.5 M CaCl2
7
Mixtures, Substances,
Compounds, and Elements
8
Separation of Mixtures
 Distillation: It separates 2 or more liquids with different
boiling points. For example: ethanol (bp: 78°C) and water
(bp: 100°C)
 Fractional crystallization: It separates 2 or more solids (by
means of precipitation) with different solubility.
 Filtration: It separates an insoluble solid from a liquid. The
solid must be insoluble in the liquid. For example: sandwater, silver chloride-water.
 Chromatography: It separates substances that are soluble
in a solvent by means of IMF.
 Evaporation: It separates a soluble solute from its solvent
by evaporating the solvent. For example: NaCl-H2O
 Liquid – liquid separation: It separates 2 immiscible liquids
using a separatory funnel. For example: oil-water
Distillation
Ethanol-water
Separates
homogeneous
mixture on the
basis of
differences in
boiling point.
10
Filtration
Separates insoluble
solid substances from
liquids and solutions.
11
Chromatography:
Separates substances on the basis of
differences in solubility in a solvent and IMF.
12
Measurements in Chemistry
Quantity
 length
 mass
 time
 current
 temperature
 amt. substance
Unit
meter
kilogram
second
ampere
Kelvin
mole
Symbol
m
kg
s
A
K
mol
13
Measurements in Chemistry
Metric Prefixes
Name
 mega
 kilo
 deci
 centi
 milli
 micro
 nano
 pico
 femto
Symbol
M
k
d
c
m
μ
n
p
f
Multiplier
106
103
10-1
10-2
10-3
10-6
10-9
10-12
10-15
14
Units of Measurement
Common Conversion Factors
 Length


Volume


2.54 cm = 1 inch
1 liter = 1.06 qt
Mass

1 lb = 454 g
15
Volume

The most commonly
used metric units for
volume are the liter (L)
and the milliliter (mL).
1 dm = 10 cm
3
3
 1 dm = 1000 cm
 1 L = 1000 mL
therefore
3
 1 mL = 1 cm

16
Uncertainty in Measurements
Different measuring devices have different
uses and different degrees of accuracy.
17
Relationships of the
Temperature Scales
Kelvin and Celsius Relationship
K = °C + 273.15
Fahrenheit and Celsius Relationship
°F = 1.8 * °C + 32
18
Use of Numbers

Exact numbers


Accuracy


1 dozen = 12 things for example
how closely measured values agree with the correct value.
The experimental value is 23.5148g, the actual value is
23.5150g. These 2 masses are accurate.
Precision

how closely individual measurements agree with each other.
The value of the mass of the same beaker in 3 trials are:
23.5148g, 23.5152g, 23.5145g. These values are precise.
19
Percent error

Percent error = accepted – experimental x 100
accepted
From previous example:
% error = 23.5150 – 23.5148 x 100 = 0.0009 %
23.5150
20
Use of Numbers


Significant Figures – Rules
All non-zero digits are significant.
Leading zeroes are never significant


Imbedded zeroes are always significant.


2.0059 has five sig fig
Trailing zeroes are only significant after the decimal
point.



0.000357 has three significant figures
1300 g has 2 sig fig
13.00 g has 4 sig fig
Use scientific notation to remove doubt
1.300 x 103 has 4 significant figures
21
Use of Numbers

Multiplication & Division rule
Easier of the two rules
Product has the smallest number of
significant figures of multipliers
4.242
x 1.23
2.7832
x 1.4
5.21766
round off to 5.22
3.89648
round off to 3.9
22
Use of Numbers

Addition & Subtraction rule
More subtle than the multiplication rule
Answer contains smallest decimal place of the
addends.
3.6923
 2.02
8.7937
 2.123
6.9463
round off to 6.95
6.6707
round off to 6.671
 1.234
23
Use of Numbers
On a multi-step question, solve all
mathematical steps and ONLY round
off the final answer.
24
Using Factor Label Method

Example: A concentrated hydrochloric acid solution is
36.31% HCl by mass. The density of the solution is
1.185g/mL. What mass of pure HCl is contained in 175
mL of this solution?
Some Possible Unit Factors from this Problem
36.31 g HCl
36.31 g HCl
63.69 g H 2 O
or
or
63.69 g H 2 O
100.00 g solution
100.00 g solution
g
density  1.185
mL
1.185 g soln 36.31 g HCl
175 mL soln 

1 mL soln 100.00 g soln
 75.3 g HCl
25
Problem 2. Calculate the volume of solution required to
prepare 0.025 M solution of Na2SO4 if only 0.050g of the
salt is available.
 Known:
 Molar mass of Na2SO4 is 142.1 g/mol.
 0.025 M means 0.025 mol/L.
26
Problem 3. Calculate the density of a cobalt(II) chloride
solution with a molarity of 3.57 M and a percent mass
by mass of 17.46%.
27
Review Nomenclature





Compounds:
Ionic
Covalent
Hydrates
Acids
Ionic compounds
Binary
Two elements
Metal
Groups IA, IIA,
Al, Ag, Zn, Cd
Only one oxidation
number
Name of the metal
does not change:
lithium, calcium
+
Ternary
More than two elements
Nonmetal
Other metals
More than one
oxidation number
Roman numerals
to specify charge:
iron(II), iron(III),
tin(II), tin(IV)
Stem of element
+ ide
oxide, sulfide,
chloride
Ionic compounds
Binary
Two elements
Ternary
More than two elements
Metal or NH4+
Groups IA, IIA,
Al, Ag, Zn, Cd
Only one oxidation
number
Name of the metal
does not change:
lithium, calcium
+
Polyatomic anion
Other metals
More than one
oxidation number
Roman numerals
to specify charge:
iron(II), iron(III),
tin(II), tin(IV)
Binary Molecular Compounds
non metal +
stem of second non metal
ending ide
Formula-to-Name Acids




Acids are molecular compounds that often
behave like they are made of ions.
All names have acid at end.
Binary Acids = Hydro- prefix + stem of the
name of the nonmetal + -ic suffix.
Oxyacids:


If polyatomic ion ends in –ate = Name of
polyatomic ion with –ic suffix.
If polyatomic ion ends in –ite = Name of
polyatomic ion with –ous suffix.
32
Hydrates

Ionic compounds that crystallize with water
occluded in their crystal structure.
NaCO3 ·10H2O

BaCl2 · 2H2O

Co(NO3) 2 · 6H20
