Introduction CHEM 012: Chemical Principles Sections Fall 2006 Instructor:Dr. Arshad Khan Office:107 Chemistry Blg Phone:(814) Office hours:Weds. 10:30-noon or by appt. Introduction CHEM 012: Chemical Principles Sections Fall 2006 Instructor:Dr. Arshad Khan Office:107 Chemistry Blg Phone:(814) Office hours:Weds. 10:30-noon or by appt.

TAs will be assisting us with this course & will be available to help you at their posted hours Chem Undergrad Office: 210 Whitmore (814) Grades Recitation days: Quiz & Homework Online skill check tests 3 Midterm exams & a final

Chapter 1 Matter and Measurement Chem 12 Penn State Dr. Arshad Khan

States of Matter Solid Solid Fixed shape, fixed volume, incompressible, particles are closely spaced and strongly held. Fixed shape, fixed volume, incompressible, particles are closely spaced and strongly held. Liquid Liquid No fixed shape, fixed volume, almost incompressible, particles are less strongly held. No fixed shape, fixed volume, almost incompressible, particles are less strongly held. Gas Gas No fixed shape, no fixed volume, compressible, particles are loosely held No fixed shape, no fixed volume, compressible, particles are loosely held

States of Matter

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

Prefixes used in Metric System Giga (G):10 9 Giga (G):10 9 Mega (M): 10 6 Mega (M): 10 6 Kilo (K):10 3 Kilo (K):10 3 Deci (d):10 -1 Deci (d):10 -1 Centi (c):10 -2 Centi (c):10 -2 Milli (m) :10 -3 Milli (m) :10 -3 Micro (μ) :10 -6 Micro (μ) :10 -6 Nano (n) :10 -9 Nano (n) :10 -9 Pico (p) : Pico (p) : Femto (f) : Femto (f) : Note: 1 kg = 10 3 g 1 km = 10 3 m

Temperature Scales  K = o C  o C = (5/9) ( o F – 32) or o F = (9/5) ( o C) + 32 (100 div./180 div.) Density Density = Mass (g) / Volume (mL) = g/mL

Extensive Property depends upon mass Extensive Property depends upon mass Examples: volume, heat Examples: volume, heat Intensive Property does not depend upon mass Intensive Property does not depend upon mass Examples: Color, Temperature, boiling temperature, etc. Examples: Color, Temperature, boiling temperature, etc.

Physical & Chemical Changes

Uncertainty in Measurement Precision Precision Reproducible Reproducible Accuracy Accuracy Correct and Reproducible Correct and Reproducible How are they different? Precision means reproducible & may be correct or incorrect

Significant Figures 1. Left most nonzero digit is the most significant figure (MSF). 2. When there is a decimal point, the right most digit is the least significant figure (LSF). 3. The number of digits from the MSF to the LSF is the number of significant figures.

MSF LSF (6 significant figures) 1234 = x 10 3 *no decimal point MSF LSF (4 significant figures)

1200=1.2 x 10 3 (2 significant figures) 1.20 x 10 3 (3 significant figures) x 10 3 (4 significant figures) =5.20 x (3 significant figures) Exact Numbers 12 inches = 1 foot … (∞ significant figures)

Rules of Multiplication & Division Go by minimum number of significant figures Go by minimum number of significant figures 1.0x5.3642= sig.5 sig. Drop and round off fig. fig. fig. fig. =5.4 =5.4 Round off rule Round off rule When dropping a digit greater than 5, add 1 to the preceeding digit. When dropping a digit greater than 5, add 1 to the preceeding digit. When dropping a digit equal to 5, add 1 for odd preceeding digit; otherwise, do not add. When dropping a digit equal to 5, add 1 for odd preceeding digit; otherwise, do not add.

Rule of Addition & Subtraction Go by minimum number of decimal places (dp). Go by minimum number of decimal places (dp) = = dp2 dp drop 1 dp2 dp drop = 22.4 Dimensional Analysis Problems