Acids and Bases

    Cards (50)

    • Spontaneous Reaction – reaction that occurs on its own without intervention of an external force
    • Non-Spontaneous Reaction – reaction that occurs in the presence of an outside intervention
    • Entropy (S) - is the thermodynamic quantity of randomness or disorder of particles atoms, molecules or ions.
    • Standard Entropy (Sº) - is the absolute entropy of 1 mole of a substance at standard conditions (1atm and 25ºC).
    • Gas - contains highest entropy
    • Solid - contains lowest entropy
    • Exothermic Processes - processes where heat energy is released from the system to surroundings.
    • Liquid - has higher entropy than solid but lower than gas
    • Endothermic Processes - processes where heat energy is absorbed by the system from its surroundings.
    • diamond has a lower entropy than graphite due to greater order of carbons
    • molecules with greater number of atoms have greater entropies as a result of greater number of molecular motions
    • Gas - has highest entropy because it can move freely in all directions, giving maximum disorder
    • bigger atoms have greater entropies than smaller atoms for having smaller spacing between energy levels.
    • Increase in Temperature = Increase in Entropy
    •   Endothermic Phase Changes (fusion, evaporation, sublimation) above melting/boiling/sublimation temperature
    • Exothermic Phase Changes (freezing, condensation, deposition) below freezing/condensation/deposition temperature
    • Entropy of Reaction (ΔS) - is the change in entropy from the initial state to the final state of a reaction or a process
    • Volume Changes
      A) spontaneous
      B) nonspontaneous
      C) more disordered
      D) less disordered
    • Entropy Change of the Universe - The sum of entropies of the system and surroundings
    • Second Law of Thermodynamics - In an isolated system, the entropy of the universe for a spontaneous change is increasing
    • Second Law of Thermodynamics - this law is consistent with the natural tendency for reactions to proceed with maximum entropy
    • Entropy Change by Surroundings - the heat released by the system is absorbed by the surroundings
    • Third Law of Thermodynamics - the entropy of a highly crystalline substance at the absolute zero
    • Gibbs Free Energy - Also known as Gibbs energy, is the energy available for a process to do at work
    • ΔG < 0 - reaction is spontaneous in forward direction
    • ΔG > 0 - reaction is spontaneous in backward direction
    • ΔG = 0 - reaction is spontaneous in both direction
    • Acid - can change the color of litmus from blue to red
    • Bases - Can change the color of litmus from red to blue
    • Acid - substance that produces protons (H+) or Hydronium ions (H30+)
    • Base – releases hydroxide ions (OH-)
    • AcidProton Donor
    • BaseProton Acceptor
    • Autoionization of water – water can undergo an acid-base reaction with itself to produce hydronium (or hydrogen) and hydroxide ions.
    • pH Meter - measures difference in the electric potential (or voltage) created in the presence of hydrogen ion.
    • pH – is a measure of hydrogen ion content in an aqueous solution. It is equal to the negative logarithm of hydrogen ion concentration (in mol/L) to the base 10:
    • Neutral - H+ = OH-
    • Acidic - H+ > OH-
    • Basic - H+ < OH-
    • zero - entropy change of the universe for a reversible reaction