General and Inorganic Chem Chapter 3 PDF

Chapter 3: Matter and its Properties Prepared by: AIMIE A. CASTRO, MST Instructor  Chapter 3 Subtopics: a. Pure Substances b. Mixtures c. States of Matter d. Changes in Matter e. Properties of Matter Lesson Objectives: Explain what matter is;...

Chapter 3: Matter and its Properties Prepared by: AIMIE A. CASTRO, MST Instructor  Chapter 3 Subtopics: a. Pure Substances b. Mixtures c. States of Matter d. Changes in Matter e. Properties of Matter Lesson Objectives: Explain what matter is; At the end of Distinguish mixtures from pure substances based on a set of the properties; chapter, Discuss the different states of matter; students should be Identify the key features of physical and chemical changes.; and able to: Recognize the difference between physical and chemical, and intensive and extensive, properties.  Matter is anything that What is matter? occupies space and has mass. Pure Substances Are substances that have definite and constant composition. Have a fixed set of properties.  Pure Substances Element Compounds A pure substance A pure substance consisting of only one kind consisting of two or more of atom in the form of kinds of atoms in the form homoatomic molecules or of heteroatomic molecules individual atoms. or individual atoms.  Classifying Substances When sulfur, an element, is heated in air, it combines with oxygen to form sulfur dioxide. Classify sulfur dioxide as an element or a compound. Because sulfur and oxygen are both elements and they combine to form sulfur dioxide, the molecules of sulfur dioxide must contain atoms of both sulfur and oxygen. Thus, sulfur dioxide is a compound because its molecules are heteroatomic  Mixtures A mixture is a combination of two substances or elements. Have varying physical and chemical properties.  Mixtures Homogeneous Heterogeneous Has uniform composition Mixtures in which the properties throughout. and appearance are not uniform throughout the sample. All substances exist in one Substances can exist in different state of matter. states of matter at once. Identify the following as homogeneous or heterogeneous mixtures. 1. Saltwater 2. Coffee 3. Opened soda drinks 4. Gravel and sand 5. Salad States of Matter  STATES OF MATTER SOLID LIQUID GAS It has a definite Has definite Has no fixed shape and volume but no volume or shape. volume. definite shape. Particles vibrate Particles are Particles are more tightly packed freely at high loosely packed together. than in a solid. speed.  STATES OF MATTER PLASMA Has no fixed volume or shape. Are electrically conductive, produce magnetic fields and electric currents, and respond strongly to electromagnetic forces. Lightning, electric sparks, fluorescent lights, neon lights, plasma televisions, some types of flame and the stars are all examples of illuminated matter in the plasma state.  STATES OF MATTER Bose-Einstein Condensate A state of matter that is typically formed when a gas of bosons at very low densities is cooled to temperatures very close to absolute zero. BECs have been used to create atom lasers, atomic clocks and gravitational, rotational or magnetic sensors with excellent sensitivity. Changes in Matter  Physical Changes Changes in Matter Chemical changes Physical Changes Are those in which It’s the shape, size, or reversible. state of the matter changes, but the substance is still essentially the same.  Phase Changes It is the transformation of matter from one phase to another. It always involves absorption or release of heat.  Changes in States of Matter Exothermic Reaction Endothermic Reaction A process that releases heat, A process that absorbs heat causing the temperature of the and cools the surroundings. immediate surroundings to rise. Melting Condensation Freezing Evaporation Deposition Sublimation Recombination Ionization Chemical Changes Occur when the composition of a substance is changed, which requires the breaking and forming of chemical bonds during a chemical reaction. Result in the production of a new substance, thus, it’s irreversible. Properties of Matter  Physical Properties Properties of Matter Chemical Properties  Physical Properties Are properties that can be measured or observed without changing the chemical nature of the substance. Intensive Property Extensive Property  Physical Properties Intensive Property Extensive Property - Any characteristic of - Any characteristic of matter that does not matter that depends on depend on the amount the amount of matter of the substance present. being measured. Some examples of physical properties are: - color (intensive) - density (intensive) - volume (extensive) - mass (extensive) - boiling point (intensive) - melting point (intensive)  Chemical Properties As any of a material’s properties that becomes evident during a chemical reaction, that is, any quality that can be established only by changing a substance’s chemical identity.