Chemistry lecture 2

• Chemistry


  The study of processes or changes taking place in the everyday life
• Chemistry


  • It is an empirical science. It must constantly test its ideas against the real world.
• Chemistry


  • What is the correct structural formula of nitric acid whose molecular formula is HNO3?
• Biology


  The study of life. Biology gives a preview of the different processes taking place in living organisms while chemistry gives a deeper explanation on an atomic and molecular level.
• Biochemistry


  The field that combines ideas of both Biology and Chemistry in medical careers and applications.
• Mathematics


  It is non-empirical. It does not need to match up to the real world to be "true" (valid). It deals with both real and unreal world.
• Mathematics in science


  It is a very useful and powerful tool employed in quantifying quantities in chemistry.
• Most useful mathematics for Chemistry


  • Basic Mathematics
  • Algebra
  • Statistics
  • Calculus
  • Logics
  • Group Theory
• Statistics


  1. The idea of a distribution of repeated measurements of the same quantity

  2. The idea of mean value as representative of a sample

  3. The shape of the normal distribution curve and the position of the average

  4. The idea of a standard deviation and its relationship to the width of the distribution curve

  5. The recipe for calculating variance and standard deviation for a set of measurements

  6. The standard error of the mean

  7. How to find the best straight line passing through a set of real data points and how to calculate its gradient and intercept and the errors in these
• Group Theory


  1. The idea of symmetry operations, transformations

  2. The kind of operations including rotation, reflection, translation

  3. Symmetry axis and planes

  4. The idea of a group as a set of elements satisfying 4 requirements - 1. membership of group, 2. identity element, 3. associative law, 4. inverse element

  5. Representations of Point Groups

  6. Matrices and vectors-operations

  7. Character tables
• Inductive logic


  Involves building up of ideas from a specific fact to arrive at a general conclusion
• Inductive logic


  • Water hyacinth an aquatic weed is found in diverse areas such as USA, Malaysia and South Africa. Therefore as a general rule all countries are plagued by this weed.
• Deductive logic


  A theory (premise) is used to arrive at a specific conclusion
• Deductive logic


  • If all matter is made up of very small particles which are always in motion, then diffusion must be common to all materials
• Physics


  Started on observing the physical macroscopic world
• Chemistry


  Mostly devoted to the effects of the microscopic world in the macroscopic world
• Experimental investigations in Chemistry always involve one or more applications of principles of Physics
• Measurements in Chemistry


  • Pressure
  • Volume
  • Density
  • Energy
  • Moles
  • Mass
  • Gravity
• Composition of matter and atoms

  • Matter has mass and occupies space
  • Matter consists of atoms
  • Atoms consist of subatomic particles such as electrons, protons, neutrons, positrons, quarks
• Laws of Thermodynamics


  • Enthalpy
  • Entropy
  • Free energy
• Laws of motion


  • Newton's Classical Laws of motion
• Laws of classical mechanics do not apply to electrons/protons in an atom
• Heisenberg's uncertainty principle


  If you know the position of an electron accurately, you lose all information on its momentum. Conversely, if you know the momentum of the electron, you cannot determined its position.
• Quantum mechanics


  A new field developed to explain the structure of the atom and behaviour of subatomic particles. It is all about probability.
• You need mathematics, Logic and Physics to understand Chemistry! And you need some Chemistry to understand Biology and Geology and other sciences!