GENCHEM 1_CHAPTER 1.pdf

CHAPTER 1: Matter, Change, and Measurement Prepared by: Ms. Missiah L. Peña, LPT LESSON 1: Matter and Its Properties  MgCl₂ Welcome, H₂O Chemist Babies! 3+...

CHAPTER 1: Matter, Change, and Measurement Prepared by: Ms. Missiah L. Peña, LPT LESSON 1: Matter and Its Properties  MgCl₂ Welcome, H₂O Chemist Babies! 3+ Fe Explore the wonders of Chemistry with Ma’am Missy! C₄H₁₀  What are the general properties observed from the item? What are the general properties observed from the item? What are the general properties observed from the item? What are the general properties observed from the item? What are the general properties observed from the item? What are the general properties observed from the item? What are the general properties observed from the item?  Today, you will... 1 2 3 describe and/or make a demonstrate an recognize that representation of the understanding of the substances are made up arrangement, relative properties of matter and of smaller particles spacing, and relative its various forms motion of the particles in each of the three phases of matter  PARTICULATE NATURE OF MATTER KINETIC PARTICLE THEORY states that matter is particulate in nature. matter is made up of tiny particles with empty spaces in between them. these particles, called atoms ATOMS are in constant random motion and attractive force exists between them. STATES OF MATTER  closely packed in an orderly manner. held together by strong attractive SOLIDS force. States of expands only very slight when heated Matter loosely packed together. LIQUIDS there are spaces between them. slightly compressed and has a lower density than solid. not held in fixed positions because GASES they have a lot of KINETIC ENERGY very weak force of attraction between the particles. PLASMA gaseous state of matter in which a part or all of the atoms or molecules are stripped off of electrons forming positive ions and negative electrons. AURORAS are atmospheric disturbances caused by the presence of low-density plasma. Northern Hemisphere - aurora borealis or northern lights Southern Hemisphere - aurora autralis or southern lights BOSE-EINSTEIN CONDENSATE The name is derived from the names of Albert Einstein and Satyendra Nath Bose, who predicted the Bose-Einstein condensate (BEC) in 1924. in a BEC, matter stops behaving as independent particles. it collapses into a single quantum state that can be described with a single, uniform wave function. Eric Cornell and Carl Weiman (1995) produced the first condensate experimentally. the BEC may occur when atoms have very similar (or the same) quantum levels, at temperatures very close to absolute zero. PROPERTIES OF MATTER According to changed involve during measurements of the property. PHYSICAL AND CHEMICAL PROPERTIES According to the dependence on the amount of matter. INTENSIVE AND EXTENSIVE PROPERTIES 1. PHYSICAL PROPERTIES observed without changing its composition. examples: boiling point, melting point, density, color, odor, hardness, electrical and thermal conductivities, tenacity, elasticity, and plasticity. 2. CHEMICAL PROPERTIES Substance that exhibits when it undergoes changes in composition. Example: Coal burns - it combines with oxygen gas to form the gaseous compound called carbon dioxide. PROPERTIES OF MATTER According to changed involve during measurements of the property. PHYSICAL AND CHEMICAL PROPERTIES According to the dependence on the amount of matter. INTENSIVE AND EXTENSIVE PROPERTIES  1. INTENSIVE PROPERTIES The measured value does not depend on the the amount of the sample. Properties such as density, temperature, and absorbency. 2. EXTENSIVE PROPERTIES This can be affected by the size of the and amount of the sample. Mass, length, and volume. More matter means more mass. CHANGES IN MATTER  1. PHYSICAL CHANGE Do not alter the composition of the substance. Melt, boil, freeze, dissolve, evaporate, condense, and sublime 2. CHEMICAL CHANGE Changes in the composition of substances. Cook, bake, decompose, combine, corrode, decay, grow, rust, spoil, and ferment  LESSON 2: Classification of Matter  MIXTURES They are combination of two or more substances that can be separated by physical methods. Mixtures differ from pure substances because they have variable compositions. HOMOGENEOUS MIXTURE - has uniform composition and properties as seen by the naked eye. These mixtures are also called solutions.  MIXTURES HETEROGENEOUS MIXTURE - not uniform in composition. EXAMPLES OF HETEROGENEOUS MIXTURE: Suspension - the suspended particles can be seen and are large enough to be filtered. HETEROGENOUS MIXTURES Colloids - this is where particles are bigger than those of solutions but smaller than those of suspensions. HETEROGENOUS MIXTURES Coarse mixtures - where the particles can be separated mechanically.  SEPARATING MIXTURES HETEROGENOUS: Decantation, Filtration, Flotation, Centrifugation HOMOGENEOUS: Distillation, Crystallization, Chromatography  SEPARATING MIXTURES DECANTATION - is the pouring of the liquid from a mixture to separate the liquid (decantate) from the solid particles.  SEPARATING MIXTURES FILTRATION - is the pouring of the mixture through a piece of paper (filter paper) which lets the liquid (filtrate) pass through but catches solid. SEPARATING MIXTURES FLOTATION - is the removal of suspended particles either by sedimentation or coagulation.  SEPARATING MIXTURES CETRIFUGATION - is the setting of tiny suspended particles using a centrifuge. This hastens the settling of the precipitate in a suspension.  SEPARATING MIXTURES DISTILLATION - make use of the differences in boiling points. In a mixture of two liquids, the liquid with the lower boiling point boils and changes into gas first. The gas is then condensed back to liquid (distillate). This is used to separate solid particles from liquid.  SEPARATING MIXTURES FRACTIONAL DISTILLATION - separates liquid mixtures whose components have boiling points that differ by just a few degrees. This process is used in petroleum refineries.  SEPARATING MIXTURES CRYSTALLIZATION - occurs when simple seawater is allowed to evaporate. The salt crystallizes out.  SEPARATING MIXTURES FRACTIONAL CRYSTALLIZATION - involves lowering the temperature of solutions so that the more metal component crystallizes out first. The solid is filtered out and the same process is repeated until no more solid crystallizes.  SEPARATING MIXTURES CHROMATOGRAPHY - separated by allowing it to flow along a stationary substance. The components in an ink solution can be separated by passing the solution through a piece of paper. The pigments travel at different speeds through the paper.  An element is a substance that cannot be broken down into simpler substances by a chemical change. ELEMENTS There are 118 known elements. Ninety-four (94) of the elements occur AND naturally on Earth and the rest have COMPOUNDS been produced artificially. Compounds are formed when two or more elements combine in a chemical change. They are substances that can be broken down into simpler substances only by chemical change.  LESSON 3: Scientific Measurements  Today, you will... 1 2 3 differentiate precision express measurements from accuracy; in scientific notation; use dimensional analysis in solving problems determine the number determine the density of of significant figures in a substance, and given measurements MEASUREMENTS reference standard The International System of Units (SI) In 1960, a system of units called International System of Units (SI) was established by the 11th General Conference on Weights and Measures. Le Systeme International d’Unites (French) Mass The amount of matter in an object. SI Unit - Kilogram (kg) - relatively large unit of measurement Gram (g) - more commonly used unit in mass digital platform scale triple beam balance The feat of these runners is measured in Most of our common household items are meters. One meter is equal to 3.3 feet. already in SI Units These balances are sensitive instruments that measure mass ranging from a few milligrams to a few kilograms electronic balance analytical balance Weight equal to the force of gravity on the object. this varies with location. Temperature measures the hotness or coldness of an object. determines the direction of the flow of heat. Three temperature scales: Celsius (formerly Centigrade), Fahrenheit, Kelvin. Celsius Scale the freezing point of water is 0°C and its boiling point is 100°C. Fahrenheit Scale the freezing point of water is 32°F and its boiling point is 212°F. Kelvin Scale the freezing point of water is 273.15K and its boiling point is 373K. 0 K, is called absolute zero = - 273.15 °C  Conversion Formulas Kelvin to Celsius: C = K - 273 (C = K - 273.15 if you want to be more precise) Kelvin to Fahrenheit: F = 9/5(K - 273) + 32 or F = 1.8(K - 273) + 32 Celsius to Fahrenheit: F = 9/5(C) + 32 or F = 1.80(C) + 32 Celsius to Kelvin: K = C + 273 (or K = C + 273.15 to be more precise) Fahrenheit to Celsius: C = (F - 32)/1.80  PRECISION It tells how close several measurements are to one another If the is a significant difference between among the measurements, the precision is low (poor). If the measurements differ in small amounts, the precision is high (or good). ACCURACY It tells how close a measurement is to the “true” or accepted value. A measurement that is accurate or has high accuracy is one that is close to the true value.  SIGNIFICANT FIGURES are the number of digits important to determine the accuracy and precision of measurement, such as length, mass, or volume. RULE 1: All nonzero digits are significant. RULE 2: Zeros between nonzero digits are significant. RULE 3: Zeros at the beginning of a number are not significant. They merely indicate the position of the decimal point. By writing the measurements in scientific notation, these zeros can be eliminated. RULE 4: Zeros at the end of a number and to the right of the decimal point are significant. RULE 5: Zeros at the end of a number may not be significant if they serve as placeholders to show magnitude of the number. Zero at the end of a number may be significant depending on the sensitivity of the measuring instrument. We use scientific notation to clear this ambiguity.