Chapter 1 Introduction: Matter and Measurement Chem101 Lecture Presentation Chapter 1 Introduction: Matter and Measurement John D. Bookstaver St. Charles Community College Cottleville, MO Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Chemistry In this science we study matter, its properties, and its behavior. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Matter We define matter as anything that has mass and takes up space. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Matter Atoms are the building blocks of matter. Each element is made of the same kind of atom. A compound is made of two or more different kinds of elements. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 States of Matter © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Classification of Matter Chem101 Classification of Matter © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Classification of Matter Chem101 Classification of Matter © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Classification of Matter Chem101 Classification of Matter © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Classification of Matter Chem101 Classification of Matter © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Classification of Matter Chem101 Classification of Matter © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Classification of Matter Chem101 Classification of Matter © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Classification of Matter Chem101 Classification of Matter © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Classification of Matter Chem101 Classification of Matter © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Classification of Matter Chem101 Classification of Matter Matter And Measurement © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Classification of Matter Chem101 Classification of Matter Matter And Measurement © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Classifying Matter

Properties and Changes of Matter Chem101 Properties and Changes of Matter © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Types of Properties Physical Properties… Can be observed without changing a substance into another substance. Boiling point, density, mass, volume, etc. Chemical Properties… Can only be observed when a substance is changed into another substance. Flammability, corrosiveness, reactivity with acid, etc. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Types of Properties Intensive Properties… Are independent of the amount of the substance that is present. Density, boiling point, color, etc. Extensive Properties… Depend upon the amount of the substance present. Mass, volume, energy, etc. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Types of Changes Physical Changes These are changes in matter that do not change the composition of a substance. Changes of state, temperature, volume, etc. Chemical Changes Chemical changes result in new substances. Combustion, oxidation, decomposition, etc. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Some Physical Properties Chem101 Some Physical Properties Dr. Ali Jabalameli

Some Chemical Properties Dr. Ali Jabalameli

Phase Changes are Physical Changes Chem101 Phase Changes are Physical Changes gas Boiling = liquid to ___ Melting = solid to ______ Subliming = solid to ___ Condensing = gas to _____ Freezing = liquid to ____ Deposition = gas to ____ state changes require heating or cooling the substance liquid gas liquid solid solid Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Chemical Reactions In the course of a chemical reaction, the reacting substances are converted to new substances. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Separation of Mixtures Chem101 Separation of Mixtures © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Filtration In filtration, solid substances are separated from liquids and solutions. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Distillation Distillation uses differences in the boiling points of substances to separate a homogeneous mixture into its components. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Chromatography This technique separates substances on the basis of differences in solubility in a solvent. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Units of Measurement © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. SI Units Chem101 Système International d’Unités A different base unit is used for each quantity. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Metric System Chem101 Prefixes convert the base units into units that are appropriate for the item being measured. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Conversions Convert 17.6 inches to centimeters: 17.6 in x 2.54 cm/1 in = 44.704 cm ~ 44.7 cm

Conversion with Units Raised to a Power Convert 1255 cubic centimeters to cubic inches: 1255 cm3 x 1 in3/16.387064 cm3 = 76.58479..in3 ~ 76.58 in3

© 2012 Pearson Education, Inc. Chem101 Volume The most commonly used metric units for volume are the liter (L) and the milliliter (mL). A liter is a cube 1 decimeter (dm) long on each side. A milliliter is a cube 1 centimeter (cm) long on each side. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Derived Units Derived unit – a unit formed from the combination of other units Ex: volume – measure of the amount of three-dimensional space occupied For solids: usually measured in cm3 V = s3 V = l x w x h V = π/4(d)2h V = π/6(d)3 (s = side, l = length, w = width, h = height, d = diameter, π = 3.14)

For liquid volume: (usually measured in Liter (L) or milliliter (mL) meniscus – the lowest point of the concave

The Meaning of Temperature Temperature is a measure of the average kinetic energy of the molecules in a sample Not all molecules have in a sample the same amount of kinetic energy a higher temperature means a larger average kinetic energy

Temperature Scales

© 2012 Pearson Education, Inc. Chem101 Temperature By definition temperature is a measure of the average kinetic energy of the particles in a sample. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Temperature In scientific measurements, the Celsius and Kelvin scales are most often used. The Celsius scale is based on the properties of water. 0 C is the freezing point of water. 100 C is the boiling point of water. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Temperature The kelvin is the SI unit of temperature. It is based on the properties of gases. There are no negative Kelvin temperatures. K = C + 273.15 © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Temperature The Fahrenheit scale is not used in scientific measurements. F = 9/5(C) + 32 C = 5/9(F − 32) © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Temperature Conversion Formulas:

Scientific Notation decimal exponential Chem101 Scientific Notation Scientific Notation – a system used to write very big or very small numbers in a more compact and precise way – consists of a _______ part (a number usually between 1 and 10) and an __________ part (10 raised to a particular exponent) decimal exponential 1.23 10-8 decimal part exponent part exponent x Dr. Ali Jabalameli

Scientific Notation 3.4567 x 106 1.2 x 10-7 Chem101 Scientific Notation Ex: Write the following numbers in scientific notation: 3, 456, 700 becomes ___________ 0.00000012 becomes _________ 3.4567 x 106 1.2 x 10-7 Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Derived Units Density is a physical property of a substance. It has units (g/mL, for example) that are derived from the units for mass and volume. d = m V © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Derived Units Density – units of mass divided by volume (most commonly expressed in g/cm3, g/mL, or g/L Density = mass / volume

Uncertainty in Measurement Chem101 Uncertainty in Measurement © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Uncertainty in Measurements Chem101 Uncertainty in Measurements Different measuring devices have different uses and different degrees of accuracy. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Significant Figures The term significant figures refers to digits that were measured. When rounding calculated numbers, we pay attention to significant figures so we do not overstate the accuracy of our answers. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Significant Figures All nonzero digits are significant. 3.04 Zeroes between two significant figures are themselves significant. 20509 Zeroes at the beginning of a number are never significant. 0.00007 Zeroes at the end of a number are significant if a decimal point is written in the number. 4.20 & 300.00 © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Significant Figures When addition or subtraction is performed, answers are rounded to the least significant decimal place. 5.02 x 89.665 x 0.10 = 45.0118 ~ 45 When multiplication or division is performed, answers are rounded to the number of digits that corresponds to the least number of significant figures in any of the numbers used in the calculation. 5.892 / 6.10 = 0.96590 ~ 0.966 © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Rules of Significant Figures with Addition and Subtraction Addition and subtraction using significant figures: The sum or difference has the same number of decimal places as the quantity carrying the _____________________ Ex: 5.74 0.823 + 2.641 9.204 ~ ____ fewest decimal places 9.20

Rules of Significant Figures with Multiplication/Division & Addition/ Subtraction Calculations involving both multiplication/division AND addition/subtraction: Follow order of operations. Keep track of significant figures through each step and only round at the end. Ex: 6.78 x 5.903 x (5.489 – 5.01) = 6.78 x 5.903 x 0.4790 = 19.1707 ~ ___ 19

Accuracy versus Precision Chem101 Accuracy versus Precision Accuracy refers to the proximity of a measurement to the true value of a quantity. Precision refers to the proximity of several measurements to each other. © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

Chem101 Precision & Accuracy Precision – the reproducibility of multiple measurements, it is how close the experimental values for different trials are to each other Accuracy – has to do with how close the experimental results are to the true value Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Dimensional Analysis We use dimensional analysis to convert one quantity to another. Most commonly, dimensional analysis utilizes conversion factors (e.g., 1 in. = 2.54 cm) 1 in. 2.54 cm or © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Dimensional Analysis Use the form of the conversion factor that puts the sought-for unit in the numerator: Given unit   desired unit desired unit given unit Conversion factor © 2012 Pearson Education, Inc. Dr. Ali Jabalameli

© 2012 Pearson Education, Inc. Chem101 Dimensional Analysis For example, to convert 8.00 m to inches, convert m to cm convert cm to in. 8.00 m  100 cm 1 m 1 in. 2.54 cm  315 in.  © 2012 Pearson Education, Inc. Dr. Ali Jabalameli