1Dr. M. A. MorsyChemistry Dept., KFUPM

Chem101Chem101

Chapter 01Chapter 01Chem101Chem101

Chapter 01Chapter 01Chemical Chemical

FoundationsFoundations

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Chapter 1-Preview

•significant figures•Handling numerical results

–Operational rules, unit Factor, …

•Classification of Matter–Element, compound, mixture, …

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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: