Chem

• All about chemistry
• When analysing markets, a range of assumptions are made about the rationality of economic agents involved in the transactions
• The Wealth of Nations was written

  1776
• Rational


  (in classical economic theory) economic agents are able to consider the outcome of their choices and recognise the net benefits of each one
• Producers act rationally by


  Selling goods/services in a way that maximises their profits
• Workers act rationally by


  Balancing welfare at work with consideration of both pay and benefits
• Governments act rationally by


  Placing the interests of the people they serve first in order to maximise their welfare
• Groups assumed to act rationally


  • Consumers
  • Producers
  • Workers
  • Governments
• Rationality in classical economic theory is a flawed assumption as people usually don't act rationally
• Demand curve shifting right

  Increases the equilibrium price and quantity
• Marginal utility


  The additional utility (satisfaction) gained from the consumption of an additional product
• If you add up marginal utility for each unit you get total utility
• VSEPR Theory


  Way to predict molecular geometry (shape)
• VSEPR Theory


  • There is a repulsion between valence e- pairs
• Balancing Equations


  1. Start with a word equation

  2. Convert to a formula equation (don't forget the diatomic molecules!)

  3. Balance with coefficients: balance each atom one at a time, balance polyatomic ions on each side of the equation as one unit, balance H and O last (they often appear in more than one compound)

  4. Check; if coefficients are not the lowest possible; reduce down
• Reaction Types


  • Synthesis (or composition)
  • Decomposition
  • Single Displacement (Replacement)
  • Double Displacement (Replacement)
  • Combustion
• Synthesis (or composition)


  2 or more substances combine to form 1 new substance
• Decomposition


  A single substance produces 2 or more simpler substances
• Single Displacement (Replacement)


  1 element replaces a similar element in a compound
• Double Displacement (Replacement)


  The ions of 2 compounds switch places to form 2 new compounds
• Combustion


  When a substance combines with oxygen releasing a large amount of energy in the form of light and heat
• Combustions often involve a hydrocarbon: compound containing C and H
• You must be able to do stoichiometric calculations by using the mol ratios from a balanced chemical equation
• Moles Given


  Moles Wanted
• Particles Given


  Particles Wanted
• Mass Given


  Mass Wanted
• Volume Given


  Volume Wanted
• Limiting Reagent (Reactant)


  Controls the amount of product formed, completely consumed in the reaction, "runs out" first
• Excess Reactant


  Leftover after a reaction
• Percent Yield


  Actual yield / Theoretical yield x 100%
• Theoretical yield


  Maximum amount of product (what you should "have gotten") from mass-mass (g to g) problem
• Actual yield


  Actual amount of product (what you "got") from lab result; or given in a problem
• Absolute Zero


  No molecular movement at this temperature (0 K, -273°C)
• Amorphous


  Non-crystalline substance such as glass that appears to be solid but is a super cooled liquid
• Anhydrous


  Without water
• Barometer


  A manometer used to measure atmospheric pressure
• Capillary Action


  The attraction of the surface of a liquid to the surface of a solid
• Condensation


  Change in state from a gas to a liquid
• Deposition


  Change in state directly from a gas to a solid
• Diffusion


  Mixing of 2 or more gases