Dr. M. A. Morsy Chemistry Dept., KFUPM 1 Chem101 Chapter 01 Chem101 Chapter 01 Chem101 Chapter 01 Chem101 Chapter 01 Chemical Foundations

Morsy CHEM 101-Chapter 1 2 Chapter 1-Preview This chapter covers the following: Scientific Methods Measurements used in the laboratory –Units, uncertainty, significant figures Handling numerical results –Operational rules, unit Factor, … Classification of Matter –Element, compound, mixture, …

Morsy CHEM 101-Chapter 1 3 Introduction Chemistry is all around you all the time –body, plants, cars, … etc. Chemistry is important to historians –Dinosaurs disappearance ????? {meteor}. –Decline of Roman Empire ?????? {lead poisoning}. Chemistry is important in determining a person’s behaviour –Statesville Prison (Illinois)  (violent) !!!!!!!! –Insects communications (Pheromones) !!!!!!!!!!

Morsy CHEM 101-Chapter Chemistry: An overview It is fundamentally concerned with: "How one substance changes to another" 1.How plants grow by absorbing water and Carbon dioxide? 2.How humans manufacture the proteins from the food we consume? 3.….. and on and on Goal: “Understand the concepts of Chemistry”

Morsy CHEM 101-Chapter Chemistry: An overview Water most common and important substance, is composed of two types of atoms, Hydrogen and Oxygen. Electric Current Reaction "Scientists" Scientists are usually excellent problem solvers because they have to master the scientific approach or “Scientific Method”

Morsy CHEM 101-Chapter The Scientific Method It is a systematic approach to research that includes: –Define the problem –Perform experiment and collect data –Enough data may led to "Hypothesis" Law: summary of observed behavior Theory:model attempt to explain

Morsy CHEM 101-Chapter Units of Measurement Quantitative Measurement, consists of two parts: numberscale a number and a scale (unit) In 1960, an international agreement get up a system of units called International System (SI- system) based on metric system.

Morsy CHEM 101-Chapter 1 8 Prefixes: are used to change the size of the unit Table 1.2 Prefixes Used with SI Units PrefixSymbolMeaning Tera-T10 12 Giga-G10 9 Mega-M10 6 Kilo-k10 3 Deci-d10 -1 Centi-c10 -2 Milli-m10 -3 Micro-  Nano-n10 -9 Pico-p Units of Measurement

Morsy CHEM 101-Chapter 1 9 Volume is not fundamental SI – unit, but very commonly used in chemistry, { SI derived unit for volume is cubic meter (m 3 ) } Used unit in liter = 1dm 3 1 m 3 = (10 dm) 3 = 1000 dm 3 = 1000 L 1 L = 1dm 3 = (10 cm) 3 = 1000 cm 3 (ml) 1.3 Units of Measurement

Morsy CHEM 101-Chapter Uncertainty in measurement Any measurement always has some degree of uncertainty. Record the certain digits and the first uncertain digit only. [ certain + first uncertain] The total numbers of the digits are called " Significant Figures" e.g., Volume = 22.2 ± 0.1 ml Example 1.1: What is the difference between the measurements 25.00mL and 25mL?

Morsy CHEM 101-Chapter 1 11 Precision and Accuracy 1.4 Uncertainty in measurement Errors Random error: Systematic error:

Morsy CHEM 101-Chapter 1 12 Rules for Counting Significant Figures: Nonzero integers are countable as SF. Zeros: - "Leading zeros” are not significant. e.g (2 SF) - "Captive zeros” Count as s.f. e.g.: 1.008(4 SF) - "Trailing zeros” count as s.f. eg. : 100 = 1.00 X 10 2 (3 SF) Exact numbers have an infinite number of SF e.g. 10 experiment, 5 apples, 8 books … so on... Exponential notation: it is used to express large or small numbers in the correct SF e.g  convenient  6.0 x Significant Figures (SF) and Calculations

Morsy CHEM 101-Chapter 1 13 Rules for SF in Mathematical Operations: Multiplication / Division: Final results have the same SF in the least precise measurement used in calculation. Addition / Subtraction: Final results have the same number of decimal places as the least precise numbers. 1.5 Significant Figures (SF) and Calculations

Morsy CHEM 101-Chapter 1 14 Note: Sometime you have to do multi- step conversion to get correct answer. 1.6 Dimensional Analysis conversion of a given results from one system unit to an other using "Unit Factor Method" or dimensional analysis.

Morsy CHEM 101-Chapter Temperature Engineering Science Difference Is complicated Difference Is in their zero T c = (T F -32 o F) x 5 o F/ 9 o C T F = (T 0C x 9 o F/5 o C) + 32 o F T(Kelvin) = T( o C)

Morsy CHEM 101-Chapter Density A property of matter that is often used by chemists.

Morsy CHEM 101-Chapter Classification of matter Read (pp ) and Report (HW#2): Define : Matter, Mixtures, Physical changes, Chemical Changes, Compound, and Element Define: Distillation, Filtration, and Chromatography

Morsy CHEM 101-Chapter 1 18 Chapter One: