Download - Chem101 Chapter 01
1Dr. M. A. MorsyChemistry Dept., KFUPM
Chem101Chem101
Chapter 01Chapter 01Chem101Chem101
Chapter 01Chapter 01Chemical Chemical
FoundationsFoundations
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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, …
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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) !!!!!!!!!!
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1.1Chemistry: 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”
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1.1Chemistry: An overview
• Watermost common and
important substance, is composed of two types of
atoms, Hydrogen and Oxygen.
O
H
H
HOH
Electric Current
Reaction
• "Scientists"Scientists are usually excellent
problem solvers because they have to master the scientific
approach or “Scientific Method”
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1.2 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
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1.3 Units of Measurement
Quantitative Measurement, consists of two parts:
a numbernumber and a scalescale (unit)
• In 1960, an international agreement get up a system of units called International System (SI- system) based on metric system.
Quantity Unit Abreviation Mass Kilogram Kg Length Meter m Time Second s Temperature Kelvin k Current Ampere A Amount oh sub Mole Mol Luminous int. Candela cd
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Prefixes: are used to change the size of the unit
Table 1.2 Prefixes Used with SI Units
Prefix Symbol Meaning
Tera- T 1012
Giga- G 109
Mega- M 106
Kilo- k 103
Deci- d 10-1
Centi- c 10-2
Milli- m 10-3
Micro- 10-6
Nano- n 10-9
Pico- p 10-12
1.3 Units of Measurement
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• Volume is not fundamental SI – unit, but very commonly used in chemistry,{SI derived unit for volume is cubic meter
(m3)}
Used unit in liter = 1dm3
1 m3 = (10 dm)3 = 1000 dm3 = 1000 L
1 L = 1dm3 = (10 cm)3 = 1000 cm3 (ml)
1.3 Units of Measurement
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1.4 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?
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•Precision and Accuracy
1.4 Uncertainty in measurement
•Errors
•Random error:
•Systematic error:
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Rules for Counting Significant Figures:
• Nonzero integers are countable as SF.• Zeros:
- "Leading zeros” are not significant. e.g. 0.0025 (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 102 (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 SFe.g. 0.000060 convenient 6.0 x 10-5
1.5 Significant Figures (SF) and Calculations
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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
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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.
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1.7 TemperatureEngineeringScience
DifferenceIs complicated
DifferenceIs in their zero
Tc = (TF-32oF) x 5oF/ 9oC TF = (T0C x 9oF/5oC) + 32oF T(Kelvin) = T(T(Kelvin) = T(ooC) + 273.15C) + 273.15
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1.8 Density
volume
massDensity
A property of matter that is often used by chemists.
volume
massDensity
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1.9 Classification of matter
Read (pp. 26-30)
and Report (HW#2):
• Define :Matter, Mixtures, Physical changes, Chemical Changes,Compound, and Element
• Define:Distillation, Filtration, and Chromatography
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Chapter One: