Introduction CHEM 012: Chemical Principles Sections 66-78 Fall 2006 Instructor:Dr. Arshad Khan...

IntroductionIntroduction CHEM 012: Chemical Principles CHEM 012: Chemical Principles

Sections 66-78Sections 66-78Fall 2006Fall 2006

Instructor:Instructor: Dr. Arshad KhanDr. Arshad KhanOffice:Office: 107 Chemistry Blg107 Chemistry Blg

Phone:Phone: (814) 863-9295(814) 863-9295Office hours:Office hours: Weds. 10:30-noon Weds. 10:30-noon

or by appt.or by appt.Email:Email: kub@psu.edukub@psu.edu

TAs will be assisting us with this course &TAs will be assisting us with this course &

will be available to help you at their posted will be available to help you at their posted

hours hours

Chem Undergrad Office: 210 Whitmore(814) 865-9391

Grades

Recitation days: Quiz & HomeworkOnline skill check tests3 Midterm exams & a final

Chapter 1Chapter 1Matter and MeasurementMatter and Measurement

Chem 12Chem 12

Penn State Penn State

Dr. Arshad KhanDr. Arshad Khan

States of MatterStates of Matter

Solid Solid Fixed shape, fixed volume, incompressible, Fixed shape, fixed volume, incompressible,

particles are closely spaced and strongly held.particles are closely spaced and strongly held.

LiquidLiquid No fixed shape, fixed volume, almost No fixed shape, fixed volume, almost

incompressible, particles are less strongly held.incompressible, particles are less strongly held.

GasGas No fixed shape, no fixed volume, compressible, No fixed shape, no fixed volume, compressible,

particles are loosely heldparticles are loosely held

States of MatterStates of Matter

SI UnitsSI Units

Length : Meter (m)Length : Meter (m) Mass: Kilogram (kg)Mass: Kilogram (kg)

Prefixes used in Metric SystemPrefixes used in Metric System

Giga (G):Giga (G): 101099

Mega (M): Mega (M): 101066

Kilo (K):Kilo (K): 101033

Deci (d):Deci (d): 1010-1-1

Centi (c):Centi (c): 1010-2-2

Milli (m) :Milli (m) : 1010-3-3

Micro (μ) :Micro (μ) : 1010-6-6

Nano (n) :Nano (n) : 1010-9-9

Pico (p) :Pico (p) : 1010-12-12

Femto (f) :Femto (f) : 1010-15-15

Note: 1 kg = 103 g 1 km = 103 m

Temperature ScalesTemperature Scales

K = oC + 273.15oC = (5/9) (oF – 32) or oF = (9/5) (oC) + 32

(100 div./180 div.)

DensityDensity = Mass (g) / Volume (mL) = g/mL

Extensive PropertyExtensive Property depends upon massdepends upon mass Examples: volume, heatExamples: volume, heat

Intensive PropertyIntensive Property does not depend upon does not depend upon massmass Examples: Color, Temperature, boiling Examples: Color, Temperature, boiling

temperature, etc.temperature, etc.

Physical & Chemical ChangesPhysical & Chemical Changes

Physical & Chemical ChangesPhysical & Chemical Changes

Uncertainty in MeasurementUncertainty in Measurement

PrecisionPrecision ReproducibleReproducible

AccuracyAccuracy Correct and ReproducibleCorrect and Reproducible

How are they different?How are they different?

Precision means reproducible & may be correct or Precision means reproducible & may be correct or incorrectincorrect

Significant FiguresSignificant Figures

1.1. Left most nonzero digit is the most Left most nonzero digit is the most significant figure (MSF).significant figure (MSF).

2.2. When there is a decimal point, the right When there is a decimal point, the right most digit is the least significant figure most digit is the least significant figure (LSF).(LSF).

3.3. The number of digits from the MSF to the The number of digits from the MSF to the LSF is the number of significant figures.LSF is the number of significant figures.

12.3100

MSF LSF (6 significant figures)

1234 = 1 .234 x 103

*no decimal point MSF LSF(4 significant figures)

1200 = 1.2 x 103 (2 significant figures)1.20 x 103 (3 significant figures)

1.200 x 103 (4 significant figures)

0.00520 = 5.20 x 10-3 (3 significant figures)

Exact Numbers12 inches = 1 foot12.000000… (∞ significant figures)

Rules of Multiplication & DivisionRules of Multiplication & Division

Go by minimum number of significant figuresGo by minimum number of significant figures1.01.0 xx 5.36425.3642 == 5.35.36426422 sig.2 sig. 5 sig.5 sig. Drop and round offDrop and round off

fig.fig. figfig..

== 5.45.4 Round off ruleRound off rule

When dropping a digit greater than 5, add 1 to the When dropping a digit greater than 5, add 1 to the preceeding digit.preceeding digit.

When dropping a digit equal to 5, add 1 for odd When dropping a digit equal to 5, add 1 for odd preceeding digit; otherwise, do not add.preceeding digit; otherwise, do not add.

Rule of Addition & SubtractionRule of Addition & Subtraction

Go by minimum number of decimal places Go by minimum number of decimal places (dp).(dp).

0.10.1 ++ 22.3222.32 == 22.422.422

1 dp1 dp 2 dp2 dp drop drop

= = 22.422.4

Dimensional AnalysisProblems