Download 1 - College of Arts and Sciences

6/27/2014
HOW TO PREPARE FOR EXAMS
HOW TO LEARN
People “learn” in different ways BUT
1. Students must be self motivated
1.
2.
3.
4.
UNDERSTAND examples in chapter(s)
WORK practice exercises in chapter(s)
Work problems at end of chapter
Use web sites such as:
2. Students must be actively involved
http://wps.prenhall.com/esm_brown_chemistry_9/1,4647,169060,.html
3. Knowledge is understanding
5. Finally test yourself with old exam from my web page
4. Knowledge results ONLY through Active
Participation
Use “Blank” area on top of Back of Scantron to
write nomenclature
Exam
27 Multiple Choice Questions
and a
10 Point Bonus Question
---------------------------------------------------------------------------------
Bonus Question on back of Scantron (# 882)
As Shown ONLY
Write Names here
Write Formulas here
1.
1.
2.
NAME ____________ 2._
3.
3.
4.
4.
5.
5.
Example of using “Blank” area on top of Back of
Scantron to write nomenclature
Write Names here
Write Formulas here
1. Silver
1. AgCl
2. Oxygen
2. H2SO4(aq)
3. Elemental Oxygen
3. CaO
4. Carbon
4. CCl4
5. Alpha particle
5. 11H+1
Chapter 1
•
•
•
•
•
Classification of Matter
Properties of Matter
SI Units
Uncertainty in Measurement
Dimensional Analysis
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What Elements & Compounds
are you expected to know ?
Properties of Matter
Intensive Properties do not depend on amount
• Elements ………Table 1.2 + ones I introduced
• Compounds ……Table 1.1 + ones I introduced
What Units of Measurement
are you expected to know ?
• SI Base Units …………..Table 1.4
• Prefixes ………………….Table 1.5
• Conversion Factors …….. Back of Book
ACCURACY & PRECISION
• ACCURACY refers to how closely a
measured value agrees with the correct
value
• PRECISION refers to how closely
individual measurements agree with one
another.
Such as density
and temperature
Density 
Kelvin (K)
weight
volume
↔
Celsius (°C)
Celsius (°C) ↔ Fahrenheit (°F)
Extensive Properties do depend on amount
such as weight, volume, etc
The Scientific Method
• Defining a Problem
• Designing an Experiment
• Collecting Data
• Interpreting Results
Exponential Notation
In Scientific Notation, Numbers Are
Written in The EXPONENTIAL Format
A x 10 n
5687.62 meters = 5.68762 x 10 3 meters
= 5.68762 Kilo meters
= 5.68762 km
Dimensional–Analysis method for
SOLVING PROBLEMS makes
use of conversion factors
Use UNITS To Solve Problems
!!!!!!
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Convert some number of pm to meters
Let UNITS SOLVE the problem !!!!!
m
pm x
 meters
pm
Units FIRST then numbers
some number pm x
1x 10-12 m
 answer in meters
1
pm
TYPES OF NUMBERS
EXACT & APPROXIMATE (MEASURED)
SAMPLE EXERCISE 1.5
What difference exists between 4.0 g and 4.00 g?
A mass of 4.0 g indicates that the uncertainty is in
the first decimal place of the measurement. Thus,
the mass might be anything between 3.9 and 4.1
Density
• Density relates the mass of an object to its
volume.
weight
Density 
volume
Convert 1.000 inches to cm
Let the UNITS solve the problem
inches x
( number )
? cm
 cm
? in
Units FIRST then numbers !!
1.000 inches x
2.54 cm
 2.540 cm
1 in
SIGNIFICANT FIGURES
1. Digits of a measured number that have
uncertainty only in the last digit
2. The NUMBER Of Digits That Are
KNOWN With CERTAINTY
3. Digits that indicate the precision of
measurements
Temperature Conversions
Kelvin (K)
↔
Celsius (°C)
Kelvin (K) = °C + 273.15
Celsius (°C) ↔ Fahrenheit (°F)
5
C  ( F  32) and
9
9 
 F   C   32
5 
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Predicting Ionic Charge
How do I know what the formula for Magnesium sulfate is
Magnesium ion: Mg 2+ & sulfate ion SO 2+2 = -2
Mg SO4
How do I know that the sulfate ion is -2?
Because I know the formula for sulfuric acid
+2
= -2
H2 SO4 (aq)
Why is Calcium Phosphate’s formula Ca3(PO4)2
Calcium ion Ca 2+ &
Chapter 2
Phosphate ion PO4 3–
+6 = -6
Ca3 (PO4)2
How do I know the Phosphate ion is -3 ?
Because I know the formula for Phosphoric acid
• Atomic Theory of Matter by Dalton
• Atomic Structure by Rutherford
– atomic numbers, mass numbers, and isotopes
– notation
+3 = -3
H3 PO4
Periodic Table of the
ELEMENTS
Atoms , Elements & Compounds
• ATOMS : The smallest representative particle of
an Element
• ELEMENTS Are Fundamental Substances
That Can Not Be Broken Down Chemically
• A COMPOUND Is A PURE Substance
Formed When TWO or More ELEMENTS
Combine
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Experiments and Observations
of Atomic Structure
Types of Radiation
alpha() beta() gamma()
 and  radiation are both affected
by an electric field
while  radiation is unaffected
1.
2.
3.
4.
5.
Dalton
Thomson
Millikan
Becquerel
Rutherford
Explained by
ATOMS
The Rutherford Model of Atomic Structure
The Modern View of Atomic Structure
The Nucleus,
containing
__________
(protons an neutrons)
is surrounded
by __________
Notation For Atoms
Relative Weight of ATOMIC PARTICLES
Name
Charge
Proton
+1
Neutron
0
Electron
-1
Mass (amu)
1
1
0
Mass Number
Symbol
A
 X
Atomic Number  Z
Mass Number = Protons + Neutrons
Atomic Number = Number of Protons
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Isotopes
What is an ALPHA particle?
An  Particle is the
Helium nucleus
4
2+
He
2
• Element with the same number of protons but
different numbers of neutrons
Isotopes of Atomic Carbon 612C
6
13 C
6
14C
WHICH ONE IS RADIOACTIVE ?
Number of Protons ?
Number of Neutrons ?
Number of Electrons ?
2
2
0
• Average Isotopic Mass: A weighted
average of the isotopic masses of an
element’s naturally occurring isotopes.
The chemical symbol for an element with 22
protons, 26 neutrons, and 19 electrons is
• The number of protons (22) is
the atomic number so the
element is titanium
• The mass number of this isotope is
the sum of the protons and neutrons
• The ion has three more protons
than electrons
Ti
22 + 26 =
48
48Ti3+
Anatomy of a Chemical Equation
CH4(g) + 2O2(g)
Reactants appear on the
left side of the equation
CO2(g) + 2H2O(g)
Products appear on the
right side of the equation.
The states of the reactants and products are written
in parentheses to the right of each compound
Coefficients are inserted to balance the equation
Chapter 3
STOICHIOMETRY
Stoichiometry: The chemical arithmetic used to
relate the amount of products and reactants to
each other in Chemical Reactions
CHEMICAL REACTIONS
1st Write Chemical Reaction
2nd Balance Reaction
3rd Interpret Reaction
A Couple of Important Reactions
1. Ammonia reacts with nitric acid to produce the
fertilizer ammonium nitrate.
Write the reaction
NH3 (g) + HNO3 (aq)  NH4NO3 (s)
Is the reaction balanced?
2. When nitroglycerin C3H5N3O9 explodes, water,
nitrogen, carbon dioxide, and oxygen form
Write the reaction
C3H5N3O9(liq)  N2(g) + O2(g) + H2O(g) + CO2(g)
Is the reaction balanced?
© 2012 Pearson Education, Inc.
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CHEMICAL REACTIONS
(YOU SHOULD KNOW)
Chemical Reaction (you should know)
COMBUSTION of a HYDROCARBON
Reaction of a hydrocarbon with oxygen
1. COMBUSTION
(Of a Hydrocarbon)
2. NEUTRALIZATION
(Acid + Base)
3. ACID + ACTIVE METAL
4. FORMATION Reaction
ACIDS You Should Know
1.
2.
3.
4.
5.
6.
7.
8.
HCl (g)
HCl (aq)
HNO3 (aq)
HC2H3O2 (aq)
H2CO3 (aq)
H2SO4 (aq)
H3PO4 (aq)
H3BO3 (aq)
Hydrogen Chloride
Hydro Chloric Acid
Nitric Acid
Acetic Acid
Carbonic Acid
Sulfuric Acid
Phosphoric Acid
Boric Acid
Types of Formulas
Methane
Ethane
Ethylene
Propane
Propylene
Butane
Some Simple Hydrocarbons
CH4
Methanol CH3OH
Ethanol
C2H5OH
C2H6
C2H4
C3H8
Propanol C3H7OH
C3H6
C4H10
Butanol
C4H9OH
Chemical Formulas & Formula Weights
Formula Weight is a conversion factor
between moles and grams
Formula Weight 
grams
mole
Formula Weight = the sum of the atomic weight
of each atom in its chemical formula.
Therefore MUST know chemical formula
before formula weight can be calculated
What is molecular mass of aspartame, C14H18N 2O5
the artificial sweetener marketed as NutraSweet ?
• Empirical formulas give the lowest
14 x 12.0 + 18 x 1.0 + 2 x 14.0 + 5 x 16.0 = 294.3 g/mol
whole-number ratio of atoms of each
element in a compound.
How many moles in 1.00 mg of aspartame ?
• Molecular formulas give the exact
number of atoms of each element in a
compound.
(1.00 mg = 1.00 x 10-3 g)
1 .00 x10 g  x 2941 .3 mol
g
-3
 3 .398 x10  6
3.40 x 10-6 mol
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Avogadro’s number is chosen so that
1 mole of 12C atoms
has a mass of exactly 12 grams.
6 protons x 1.66 x 10-24 grams = 9.96 x 10-24
6 neutrons x 1.66 x 10-24 grams = 9.96 x 10-24
So 12 C weighs 19.92 x 10 -24 grams
(19.92 x 10 -24) x (X ) = 12 grams
Solve for X
X = 6.0249638 x 1023
From khanacademy.org on Youtube
• The mole and avogadro's number
http://www.youtube.com/watch?v=AsqEkF7h
cII&feature=related
• Balancing Chemical Equations
http://www.youtube.com/watch?v=RnGu3xO
2h74&NR=1
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