Chemistry Preliminary Course 2011 Dr Mike Lyons School of Chemistry Trinity College Dublin INTRODUCTION TO CHEMISTRY Chemistry Preliminary Course 2011 12/09/2011 Dr Mike Lyons Room 3.2 School of Chemistry Trinity College Email: melyons@tcd.ie Chemistry Preliminary Course 2011 12/09/2011 Welcome to CHEMISTRY !!! An Observational Science An Experimental Science A Laboratory Science An Interesting Science An Important Science A ―Hard‖ Science A science rooted in the real world ! Chemistry Preliminary Course 2011 12/09/2011 What is chemistry? Chemistry is the science which deals with the composition and properties of material substances, and the reactions by which one substance is converted into another Chemistry is a core science and along with Physics and Biology provides an understanding of the material universe Chemistry Preliminary Course 2011 12/09/2011 Chemistry as the Central Science Oceanography Atmospheric Sciences Physics Economics Medicine Governments Chemistry Advanced Materials Geology Archeology People Biology Politics Astronomy Chemistry Preliminary Course 2011 12/09/2011 Chemistry …the experimental science Chemistry Preliminary Course 2011 12/09/2011 Chemistry Preliminary Course 2011 12/09/2011 Chemistry Is a social activity science distributed via human interaction Chemistry Preliminary Course 2011 12/09/2011 Chemistry: the major subject areas Physical Chemistry Organic Chemistry Inorganic Chemistry Analytical Chemistry Biochemistry Environmental Chemistry Medicinal Chemistry Computational Chemistry Materials Chemistry Chemical Physics Biological Chemistry Many of these topics will be studied in the Chemistry course at Trinity At the research level, chemists may work in more than one of these areas, and may be involved in research programmes straddling disciplines such as physics and molecular biology Chemistry Preliminary Course 2011 12/09/2011 The scientific method… … The best baloney detector there is … Use scientific method to distinguish Between science and pseudo-science Define/Identify the Problem Form a Hypothesis Make Observations or Test Hypothesis and Perform Experiments Organize and Analyze Data Do Experiments and Observations Support Hypothesis? If No, Perform New Experiments and Repeat Step Draw Conclusions Communicate Results Chemistry Preliminary Course 2011 12/09/2011 10 Common Decimal Prefixes Used with SI Units Prefix Prefix Symbol tera giga mega kilo hecto deka deci centi milli micro nano pico femto T G M k h da -d c m n p f Number Word 1,000,000,000,000 trillion 1,000,000,000 billion 1,000,000 million 1,000 thousand 100 hundred 10 ten one 0.1 tenth 0.01 hundredth 0.001 thousandth 0.000001 millionth 0.000000001 billionth 0.000000000001 trillionth 0.000000000000001 quadrillionth Chemistry Preliminary Course 2011 12/09/2011 Exponential Notation 1012 109 106 103 102 101 100 10-1 10-2 10-3 10-6 10-9 10-12 10-15 44 Derived SI Units Quantity Area Volume Definition of Quantity Length squared Length cubed SI unit m2 m3 Density Mass per unit volume Speed Distance traveled per unit time Acceleration Speed changed per unit time m/s2 Force Mass times acceleration of object Pressure Force per unit area Energy Force times distance traveled kg m/s2 ( =newton, N) kg/(ms2) ( = pascal, Pa) kg m2/s2 ( = joule, J) Chemistry Preliminary Course 2011 kg/m3 m/s 12/09/2011 45 Length Volume Chemistry Preliminary Course 2011 Mass 12/09/2011 46 Chemistry Preliminary Course 2011 12/09/2011 47 Chemistry Preliminary Course 2011 12/09/2011 48 Chemistry Preliminary Course 2011 12/09/2011 49 Scientific research …is a human activity Trinity Electrochemical Energy Conversion & Electrocatalysis Group Chemistry Preliminary Course 2011 12/09/2011 50 The Ying / Yang of Electrochemistry Isolated oxidation and reduction processes are not much good These reactions must be coupled together in some way to perform a technologically useful function An electrochemical cell is formed by coupling together individual oxidation and reduction processes in a specific configuration to form a useful device There are two types of electrochemical cells based upon the general thermodynamic nature of the reaction (expressed as whether the change in Gibbs energy is positive or negative Oxidation and reduction reactions occurring at individual electrode/electrolyte interfaces can be coupled together either to produce an electrical voltage or to produce chemicals • Galvanic cell – This is an electrochemical power source – The cell does work by releasing free energy from a spontaneous reaction to produce electricity • Battery • Fuel cell • Electrolytic cell – This is an electrochemical substance producer – The cell does work by absorbing free energy from a source of electricity to drive a nonspontaneous reaction • Electrosynthesis • Electroplating Chemistry Preliminary Course 2011 12/09/2011 51 The Hydrogen Economy: Hydrogen as an energy carrier G.W Crabtree, M.S Dresselhaus, M.V Buchanan, ‗The hydrogen Economy‘ Physics Today, Dec.2004, pp.39-45 U Bossel, ‗Does a hydrogen economy make sense?‘ Proc IEEE, 94 (10)(2006), pp.18261836 Chemistry Preliminary Course 2011 P.P Edwards, V.L Kuznetsov, W.I.F David, N Brandon Energy Policy 36(2008) 4356-4362 12/09/2011 52 Electrochemical energy conversion and storage Water Electrolysis Cells OER, HER Chemistry Preliminary Course 2011 Electrochemical Energy Storage Redox switching Redox Capacitance Polymer Electrolyte Membrane (PEM) Fuel Cells ORR 12/09/2011 53 The electrolysis of water Weinberg, J Chem Ed.,60 (1983) 268-271 Overall (cell) reaction 2H2O(l) 2H2(g) + O2(g) Oxidation half-reaction 2H2O(l) H+(aq) + O2(g) + 4e- Reduction half-reaction 4H2O(l) + 4e2H2(g) + 4OH-(aq) Copyright © The McGraw-Hill Companies, Inc Permission required for reproduction or display Chemistry Preliminary Course 2011 12/09/2011 54 Burke-Lyons Duplex Layer Model Oxide/solution interface HYDROUS OXIDE METAL =O COMPACT OXIDE = Fe = Na+(aq) = OH- [Ni(III)Om(OH)n]p- + OH- → [Ni(III)Om+1(OH)n-1]p- + H2O + e[Ni(III)Om+1(OH)n-1]p- → [Ni(III)Om OOH(OH)n-2](p-1)- + e- …RDS [Ni(III)Om OOH(OH)n-2](p-1)- + 2OH- → [Ni(III)Om O2 (OH)n-1]p- + H2O + e[Ni(III)Om OO(OH)n-1]p- + OH- → [Ni(III)Om(OH)n]p- + O2 + e- (a) (b) (c) M.E.G Lyons, M.P Brandon Phys.Chem Chem Phys., 11(2008) 2203 M.E.G Lyons, M.P Brandon, J Electroanal Chem., 631 (2009) 62 M.E.G Lyons, M.P Brandon, J Electroanal Chem., 641 (2010) 119 Metal oxide plays intrinsic role in OER Chemistry Preliminary Course 2011 12/09/2011 55 Chemistry Preliminary Course 2011 12/09/2011 56 Recommended Reading : Maths & Physics for Chemistry Maths for Chemistry, 2nd Edition Paul Monk & Lindsey J Munro, Oxford, 2010 Foundations of Physics for Chemists, G.A.D Ritchie & D.S Sivia, Oxford Chemistry Primers 93, Oxford, 2000 Basic algebraic manipulations Properties and applications of logarithms Solving linear and quadratic equations Simple differentiation and integration Simple differential equations Chemistry Preliminary Course 2011 12/09/2011 57 Summary Chemistry is the central science and is understood via a molecular perspective Chemistry is the basis of modern biology Chemical manipulations provides the materials which underlie much of modern life Chemistry Preliminary Course 2011 Science, via application of the scientific method, provides a firm basis to understand physical reality, and to enable one to distinguish between useful information and nonsense Need a minimum basis of Maths & Physics to succeed at Chemistry 12/09/2011 58 ... Physical Chemistry Organic Chemistry Inorganic Chemistry Analytical Chemistry Biochemistry Environmental Chemistry Medicinal Chemistry Computational Chemistry Materials Chemistry Chemical... Energy Freezing Solid Chemistry Preliminary Course 2011 12/09/2011 28 General Features of the Atom Chemistry Preliminary Course 2011 12/09/2011 29 Chemistry Preliminary Course 2011 12/09/2011... 2011 12/09/2011 Chemistry Preliminary Course 2011 12/09/2011 Chemistry Is a social activity science distributed via human interaction Chemistry Preliminary Course 2011 12/09/2011 Chemistry: the