CHM012_Intro to Chem for Engineers (1).pdf

CHEM012 (Chemistry for Engineers Lecture) INTRODUCTION TO CHEMISTRY FOR ENGINEERS Lecturer: Heart P. Beldad Course Outline CHEMISTRY OF 1 ENGINEERING MATERIALS 2 ENERGY AND CHEMISTRY 3 ELECTRO- CHEMISTRY 4 NUCLEAR...

CHEM012 (Chemistry for Engineers Lecture) INTRODUCTION TO CHEMISTRY FOR ENGINEERS Lecturer: Heart P. Beldad Course Outline CHEMISTRY OF 1 ENGINEERING MATERIALS 2 ENERGY AND CHEMISTRY 3 ELECTRO- CHEMISTRY 4 NUCLEAR CHEMISTRY CHEMISTRY OF THE 5 ENVIRONMENT Chemistry for Engineers Chemistry- “science of matter” Engineering designs involve matter. The links between chemistry and engineering are many. Chemistry for Engineers States of Matter Source:https://byjus.com/question-answer/name-the-branch-that-studies-particle-behaviour/ States of Matter Solids has a definite shape and volume. rigid do not change their shape easily. atoms are tightly packed together. What makes solids so strong? Because of the strong intermolecular force and thermal energy of the system. Source: https://th.bing.com/th/id/R.650151fa93007dbf12cfb252b6c47fbf?rik=i6xqof38cKfYlA&riu=http%3a%2f%2fwww.randrmagonline.com%2fext%2fresources%2f2016%2fMay%2fweb- exclusives%2fFig_1_Solid_Liquid_Gas_Heat.jpg&ehk=Dyk%2fyZhI51AslA3QiRaPE6IWbUNDg6xoywKILKV7YM8%3d&risl=&pid=ImgRaw&r=0 Low temperature= Low thermal energy = Less movements of particles = strong intermolecular force = strong solids. Strong intermolecular force= strong attraction between molecules= condensed state  Atoms in solids can be thought as... billiard balls in a box marbles in a box Source: https://thumbs.dreamstime.com/b/glass-marbles-box-22208014.jpg Source: https://media.istockphoto.com/id/185976559/photo/billiard-balls-in-wooden-box.jpg?s=612x612&w=0&k=20&c=XNwG5H23By4OOMTuvypbs1USqnpLUZjfixL7V9i9uzo= Atoms are arranged... Source: https://chemistrywithmehule.files.wordpress.com/2022/12/screenshot_2022_1208_230800.jpg Crystalline- solid atoms assuming regular and repeating geometric arrangements, Amorphous- solid atoms that solidify into random arrangements. Crystalline & Amorphous Solids Examples: Table Salt Cotton Candy (Crystalline solid) (Amorphous solid) Two (2) different ways to stack the spheres/atoms to achieve maximum packing density 1. Cubic-close packaging (CCP) features a layering pattern “ABCABC” repeats every three layers leading to a cubic structure. 2. Hexagonal-close packaging (HC features stacking sequence of “ABAB” repeats every two layers leading to a hexagonal structure. Source: Brown & Holme (2011) Three Cubic Lattices Source: Brown & Holme (2011) This figure shows how atoms are placed in a cube. Three Cubic Lattices Source: https://th.bing.com/th/id/OIP.Q5DhgiovYJRuIBrL2skcJwAAAA?rs=1&pid=ImgDetMain Three Cubic Lattices Simple cubic crystal (SCC) lattice atoms are located at each of the corners of a cube. Body-centered cubic crystal (BCC) lattice an additional atom is placed at the center of the cube. Face-centered cubic crystal (FCC) lattice additional atoms are placed on each of faces of the cube. Intramolecular Forces vs. Intermolecular Forces Source: https://cdn.clutchprep.com/guide_visuals/inline_images/Sb9OoXBMiTgVoII8mgpNfw.png Intramolecular Forces Why such a difference in bond polarity? Due difference in electronegativity Intramolecular Forces Electronegativity Chemical Bond Difference < 0.5 Nonpolar covalent 0.5- 2.0 Polar covalent > 2.0 Ionic bond Example: Electronegativity of carbon: 2.5 Electronegativity of hydrogen: 2.1 Electronegativity difference: 0.4 Type of chemical bond: nonpolar covalent Intramolecular Forces Intermolecular Forces (IMFs) forces that are largely responsible for determining the structure and properties of solids. Strong intermolecular forces between atoms in a solid have a significant impact on its physical properties. Source: https://i.ytimg.com/vi/u57gISjF8Uo/maxresdefault.jpg Types of IMFs Dispersion Forces (London Dispersion Force) common to all molecules weakest force because dipoles are short-lived Dipole-dipole occur between molecules that have permanent dipoles stronger than LDF but weaker than hydrogen bonding. Hydrogen bonding present between molecules both containing H covalently bonded to F, O, or N. Strongest among LDF and dipole-dipole because of high difference in electronegativities. Intermolecular Forces Nonpolar compound: LDF Polar compound: LDF, dipole-dipole H bonded to F, O, N: LDF, dipole-dipole, hydrogen bonding  PRACTICE: Determine the IMF(s) present in the ff substances: Note: A compound is nonpolar if: Central atom has no lone pairs All atoms around the central atom are the same. All hydrocarbons are nonpolar. Single Element= Nonpolar Assignment No.1 (Individual) As an engineering student, why is it important for you to learn chemistry concepts? Provide one real-life example or application of chemistry concepts relevant to your course. Scan to submit Note: Maximum word count: 200 words. Submit your answers through this link: https://tinyurl.com/bdf9feax Deadline: September 8, 2024 (11:59 pm)