Chapter One Chemical Foundations

Section 1.1 Chemistry an Overview Macroscopic World Macroscopic World Microscopic World Microscopic World Process for Scientific Study Process for Scientific Study –Making Observations –Making a Prediction –Doing experiments

Section 1.2 Scientific Method Steps Steps –Making observation Quantitative Quantitative Qualitative Qualitative –Formulating hypotheses –Performing experiments Theory Theory Model Model Natural Law Natural Law Law of Conservations of Mass Law of Conservations of Mass

Section 1.3 Units of Measurement A measurement consists of two parts – the actual number and the unit A measurement consists of two parts – the actual number and the unit SI system SI system Derived unit Derived unit Volume Volume –Tools used to measure liquid volume Mass Mass Weight Weight

Section 1.4 Uncertainty in Measurement Certain digits Certain digits Uncertain digits Uncertain digits Significant figures in measurement Significant figures in measurement Precision and Accuracy Example: Example: See page 12 Exercise 1.1 Example: Example: See page 14 Exercise 1.2

Section 1.5 Significant Figures and Calculations Rules for Counting Significant Figures Rules for Counting Significant Figures –Nonzero integers –Zeros –Exact numbers Nonzero integers always count as significant figures Nonzero integers always count as significant figures Leading zeros – Leading zeros – Captive zeros – Captive zeros – Trailing zeros – Trailing zeros – Exact Numbers Exact Numbers

Section 1.5 Significant Figures slide 2 Rules for Significant Figures in Mathematical Operations Rules for Significant Figures in Mathematical Operations –For multiplication and division, the number of significant figures in the result is the same as the number in the least precise measurement used in the calculation. –For addition or subtraction, the result has the same number of decimal places as the least precise measurement used in the calculation Rules for Rounding Rules for Rounding –In a series of calculations, carry the extra digits through to the final result, then round. –If the digit to be removed A. is less than 5, the preceding digit stays the same. For example, 1.33 rounds to 1.3 A. is less than 5, the preceding digit stays the same. For example, 1.33 rounds to 1.3 B. is equal to or greater that 5, the preceding digit is increased by 1. B. is equal to or greater that 5, the preceding digit is increased by 1.

Section 1.6 Dimensional Analysis Converting from One Unit to Another Converting from One Unit to Another –To convert from one unit to another, use the equivalence statement that relates the two units –Derive the appropriate unit factor by looking at the direction of the required changes (to cancel the unwanted units). –Multiply the quantity to be converted by the unit factor to give the quantity with the desired units.

Section 1.7 Temperature Three temperature scales Three temperature scales –Fahrenheit –Celsius (Kelvin – ) –Kelvin (Celsius )

Section 1.8 Density Density – a property of matter that is often used by chemists as an “identification tag” for a substance. Density – a property of matter that is often used by chemists as an “identification tag” for a substance. Density equals mass divided by volume Density equals mass divided by volume D = m/v

1.9 Classification of Matter Matter Matter –States –Pure substance –Mixtures Homogeneous Homogeneous –solution Heterogeneous Heterogeneous

Section 1.9 Classification of Matter Slide 2 Changes Changes –Physical –Chemical Compound Compound element element Methods for separation Methods for separation –Distillation –Filtration –Chromatography paper chromatography paper chromatography