Chemistry For Engineers - Lec PDF

CHEMISTRY FOR ENGINEERS - LEC MATTER  Discuss what is matter, its properties, states and the classifications of matter. LEARNING Differentiate physical changes from chemical OUTCOMES: changes Differentiate the different...

CHEMISTRY FOR ENGINEERS - LEC MATTER  Discuss what is matter, its properties, states and the classifications of matter. LEARNING Differentiate physical changes from chemical OUTCOMES: changes Differentiate the different classification of matter and provide some examples that are related in engineering program.  Matter refers to anything that occupies space and has mass. MATTER Can you give some examples of matter? How about example that is not matter?  PROPERTIES PROPERTIES - qualities or characteristic 1. EXTENSIVE PROPERTY - also known as extrinsic property - property that can vary with different samples of the same material - are not inherent characteristics of the material itself. Ex. Mass, volume, size, length  PROPERTIES 2. INTENSIVE PROPERTY - also known as intrinsic property - property that does not change with different samples of the same material - inherent characteristics of the substances and depend on the kind of material itself. Ex. Color, odor, taste, hardness, solubility, density, melting point, boiling point  MATTER IS IDENTIFIED THROUGH ITS INTENSIVE PROPERTY 1. Physical Property - properties that can be observe without changing the composition of the substances. Ex. Color, odor, taste, hardness, density, solubility, melting point, boiling point  COMPOSITIONS Elements present COMPOUNDS Proportion Ex. Hydrogen & Oxygen H2O 11 % by weight H 89 % by weight O 2. Chemical Property - properties that can be observed when a chemical change takes place in a substance. - properties that strikes how a substance interest another. Ex. Combustibility - ability of a substance to burn Reactivity - rusting of iron CHANGES OF MATTER 1. Physical Change - alters the form but not the composition of the substance - change in state  CHANGES OF MATTER 2. Chemical Change - change that alters by forming a new substances - change in the composition - associated with chemical properties INDICATIONS OR PREDICTIONS OF CHEMICAL CHANGE 1. change in color 2. evolution of gas 3. evolution or absorption of heat CHANGES OF MATTER STATES OF MATTER 1. Solid 2. Liquid 3. Gas  STATES OF MATTER SOLID LIQUID GAS  COMPARISON BETWEEN A SOLID, LIQUID, GAS Property Solid Liquid Gas Particle packed not widely widely Arrangement closely separated separated together Movement very little slower than Freely gas Diffusion very slow slower than Easily gas Compressibility very difficult readily difficult Density high high Low Mixability extremely slower than readility slow gas  CLASSIFICATIONS OF MATTER MATTER SUBSTANCES MIXTURES ELEMENT COMPOUND HOMOGENEOUS HETEROGENEOUS SOLUTION COLLOID SUSPENSION  SUBSTANCES - have constant composition and can only be separated by chemical reactions  ELEMENT - substances that cannot be decomposed into simpler substances by chemical or physical means  COMPOUND - substance with constant composition that can be broken down into elements by chemical processes  MIXTURES - consist of 2 or more substances - does not have a fixed composition and maybe separated into its components by physical means  HOMOGENEOUS - mixture of 2 or more pure substances that is uniform throughout  HETEROGENEOUS - not uniform throughout but consists of parts that are physically distinct  HETEROGENEOUS Colloids - A mixture that contains dispersed particles that are intermediate in size between those of a true solution and suspension Suspension - heterogeneous mixture containing solid particles that are sufficiently large for sedimentation  REFERENCES Hill, John W. (2013). Chemistry for Changing Times. New York: Prentice Hall Stoker, H. Stephen (2016). General Chemistry. Andover: Cengage Learning Asia Pte Ltd. Zumdahl, Steven S. (2015). Introductory Chemistry: A Foundation. USA: Cengage Learning Asia Ptd Ltd., USA