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• Chemical equilibrium

  When the rate of forward reaction = the rate of backwards reaction
• Reactants → products and products → reactants


  At equilibrium the forward and reverse reactions are still happening
• Equilibrium constant K

  [products] / [reactants] where the concentration of that substance is raised to the power of its stoichiometric coefficient. K also depends on the particular reaction and the temperature and its unit less
• Solids are not included in the reaction as the density fixes the concentration of the solid
• Reactions also involving pure liquids are also omitted from the equation as the concentration of the liquid is very high and does not change
• Equilibrium constant K for gases


  Can be expressed as the partial pressure of the gasses in the reaction
• Forward and reverse reactions and equilibrium constant K


  Have a direct relationship. Kfor = 1/Krev
• Situations considered

  • K<<1
  • K>>1
• Le chatelier's principle

  When a system is at equilibrium and a stress is applied, the system will alter the equilibrium in a way to minimize the stress
• Examples of stress

  • Change in temperature
  • Change in concentration
  • Change in volume
  • Change in pressure
• Increasing products/decreasing reactants


  Shifts equilibrium to the reactants
• Increasing reactants/decreasing products


  Shifts equilibrium to the products
• Exothermic reaction, increasing temperature


  Shifts equilibrium to the reactants
• Exothermic reaction, decreasing temperature


  Shifts equilibrium to the products
• Increasing pressure/decreasing volume


  Shifts the equilibrium to the side with fewer moles
• Altitude sickness

  At sea level, oxygen has pressure of 0.2 atm and at high altitudes oxygen has pressure of 0.14 atm. Hypoxia occurs which is the lack of oxygen in tissues. This leads to nausea, headache, sleeplessness and fatigue
• CVS and respiratory system

  Regulate the blood pH by the bicarbonate buffer system
• Body hyperventilates to compensate for lack of oxygen


  Leads to carbon dioxide being exhaled and an overall reduction in H+ ion concentration
• Respiratory alkalosis


  Occurs due to blood pH rising
• Acetazolamide


  Used to treat altitude sickness. It assists in the excretion of bicarbonate and retention of H+ ions. Due to the retention, this leads to an increase in H+ ions and therefore a decrease in blood pH