General and Inorganic Chemistry I. Lecture 1 István Szalai Eötvös University István Szalai (Eötvös University) Lecture 1 1 / 21 Outline 1 Introduction 2 3 Foundations of Chemistry István Szalai (Eötvös University) Lecture 1 2 / 21
Introduction Informations Lecture (3+2 hours/week) + laboratory practice (5 hours/week) Lecturers: Szabolcs Béni & István Szalai (II. floor room: 221) email: pisti@chem.elte.hu Laboratory supervisors: Anikó Vasanits, Viktor Mihucz Homepage: www.chem.elte.hu/departments/anal/szalai/genchem.html http://www.gytk.sote.hu/gyki/oktatok/beniszab/beniszabolcs.htm Theoretical grade: exam (oral+written) during the examination period (December-January). The theoretical exam covers the topics discussed during the lectures and the laboratory practices (calculations!). Those who failed in laboratory not allowed to take the theoretical exam, they must repeat the whole semester! István Szalai (Eötvös University) Lecture 1 3 / 21 Books Introduction Whitten, Davis, Peck, Stanley: Chemistry (Thomson Brooks/Cole, 195$) Masterton, Hurley: Chemistry Principles & Reactions (Saunders College Publishing, 147$) Ebbing D. D.: General Chemistry (Houghton Mifflin Company Boston, 141$) Schaum s Outline of College Chemistry ( 18$) Textbook: en.wikibooks.org/wiki/general Chemistry (free) István Szalai (Eötvös University) Lecture 1 4 / 21
Introduction Outline of the theoretical lecture Introduction Structure of Atoms and Molecules Chemical Reactions and Equilibrium Thermochemistry Chemical Kinetics István Szalai (Eötvös University) Lecture 1 5 / 21 Matter and Energy States of matter: Gases:They occupy all parts of any vessel in which they are confined. They are capable of infinite expansion and are compressed easily. The individual particles are quite far apart. Liquids:The individual particles are confined to a given volume. A liquid assumes the shape of the container. They are very hard to compress. Solids:They are rigid and have definite shapes. Volumes of solids do not vary much with changes in temperature. In crystalline solids the individual particles occupy definite positions in the crystal structure. István Szalai (Eötvös University) Lecture 1 6 / 21
Matter and Energy States of matter: Forms of energy: kinetic energy (E kin = 1 2 mv 2 ), potential energy (E pot = mgh), heat, electrical energy... Law of conservation of matter and energy: There is no change in the quantity of matter and energy during any chemical or physical change. István Szalai (Eötvös University) Lecture 1 7 / 21 Physical Properties A physical change occurs with no change in chemical composition. e.g.: boiling, melting, vaporization... Physical properties altered significantly as matter undergoes physical changes. Extensive properties: quantity proportional to the quantity of material in the system. mass, volume, total energy Intensive properties: independent of the quantity of material density, pressure, temperature István Szalai (Eötvös University) Lecture 1 8 / 21
SI Units length meter m mass kilogram kg time second s electric current ampere A temperature Kelvin K luminous intensity candela cd amount of substance mole mol meter: the lenght equal to the distance traveled by light in vacuum in 1/299,792,458 seconds. mol: the amount of substance that contains as many entities (atoms or other particles) as there are atoms in 0.012 kg of pure 12 6C. 1 mole = 6.022 10 23 István Szalai (Eötvös University) Lecture 1 9 / 21 Derived Units area square meter m 2 volume cubic meter m 3 density kilogram/cubic meter kg/m 3 force newton N kg m/s 2 pressure pascal Pa N/m 2 energy joule J kg m 2 /s 2 electric charge coulomb C A s electric potential difference volt V J/(A s) István Szalai (Eötvös University) Lecture 1 10 / 21
SI prefixes 10 12 tera T 10 1 deci d 10 9 giga G 10 2 centi c 10 6 mega M 10 3 milli m 10 3 kilo k 10 6 micro µ 10 2 hecto h 10 9 nano n 10 1 deka da 10 12 pico p 10 15 femto f 10 18 atto a István Szalai (Eötvös University) Lecture 1 11 / 21 Chemical properties They are exhibited by matter as it undergoes changes in composition: acidity redox properties reactivity... Chemical changes are transformations in which substances are converted into other substances. e.g..: burning, decomposition... 3 Br 2 (l) + 2 Al(s) 2 AlBr 3 (s) István Szalai (Eötvös University) Lecture 1 12 / 21
Classification of matter Mixtures: Variable composition. Components retain their characteristic properties. May be separated into pure substances by physical methods (e.g. distillation). Mixtures of different compositions may have widely different properties. Homogeneous mixtures: components are indistinguishable; have same composition throughout (e.g. solutions, alloys). Heterogeneous mixtures: components are distinguishable; do not have same composition throughout (e.g. muddy river water). István Szalai (Eötvös University) Lecture 1 13 / 21 Classification of matter Pure Substances: Fixed composition. Cannot be separated into simpler substances by physical methods. Elements: cannot be decomposed into simpler substances by chemical changes Compounds: can be decomposed into simpler substances by chemical changes, always in a definite ratio István Szalai (Eötvös University) Lecture 1 14 / 21
Compounds Law of definite proportions: pure compounds always consist of the same elements combined in the same proportion by mass. water 11,1 % hydrogen 88,9 % oxygen carbon dioxide 27,3 % carbon 72,7 % oxygen István Szalai (Eötvös University) Lecture 1 15 / 21 Compounds Law of Multiple Proportions: If two elements form more than one compound, in these compounds masses of one element that combine with a fixed mass of the other element are in a ratio of integer numbers. N:O N 2 O 1:0.57 NO 1:1.14 0.57:1.14=1:2 NO 2 1:2.28 0.57:2.28=1:3 István Szalai (Eötvös University) Lecture 1 16 / 21
Foundations of Chemistry Foundations of Chemistry Atoms: the smallest particle of an element that maintains its chemical identity. Structure of atoms: The diameter of an atom is 10 10 m (0,1 nm). The nucleus contains protons and neutrons. The diameter of a nucleus is 10 15 m. Particle Mass Charge proton 1.672 10 27 kg +1.602 10 19 C neutron 1.675 10 27 kg none electron 9.109 10 31 kg 1.602 10 19 C m(p + ) m(e ) 1840 István Szalai (Eötvös University) Lecture 1 17 / 21 Foundations of Chemistry Foundations of Chemistry Atomic number (Z) = number of protons in the nucleus Mass number (A) = number of protons + number of neutrons Symbol: A Z X, 12 6 C Isotopes: atoms for the same elements with different masses e.g 1 1 H, 2 1 H, 3 1 H Atomic mass unit: exactly 1/12 of the mass of an atom of 12 6 C (1 amu = 1.6606 10 27 kg) On this scale the atomic weight of hydrogen is 1.00794 amu. Relative atomic mass: atomic weight divided by the atomic mass unit Relative atomic weight of hydrogen is 1.00794. István Szalai (Eötvös University) Lecture 1 18 / 21
Foundations of Chemistry Foundations of Chemistry In the molecules two or more atoms are bonded together. An ion is an atom or group of atoms that carries an electric charge. Ions that possess a positive charge are called cations. Those carrying negative charge are called anions. A radicalis a group of atoms which have odd number of electrons. Isotopes: atoms for the same elements with different masses e.g 1 1 H, 2 1 H, 3 1 H István Szalai (Eötvös University) Lecture 1 19 / 21 Foundations of Chemistry István Szalai (Eötvös University) Lecture 1 20 / 21
Foundations of Chemistry István Szalai (Eötvös University) Lecture 1 21 / 21