chemical process

• what is an open system?


  Both matter and energy can exhange with the surroundings
• what is a closed system?


  Has a fixed amount of matter but can exchange energy with the surroundings
• what is the isolated system?

  Has no contact with the surroundings
• What are the three ways of changing the energy of a system?

  • Changing the amount of material
  • changing the temperature
  • doing work
• What must occur to the surroundings when comparing it to the system?

  must be equal and opposite
• what is heating?


  The transfer of energy between the system and the surrounding that occurs due to a temperature difference between them
• what is work?


  work is done is when an object is moved against an opposing force.
• what is the symbol of heat?


  q
• what is the symbol of work?

  w
• what is the equation of work?

  -P(ext)deltaV
• what is the equation for specific heat capacity?


  Q = mcΔT
• what is internal energy?


  The total energy of a system, including both its kinetic and potential energy.
• what is the equation form internal energy?


  delta U = q + w
• what is the internal energy for a isolated system?


  0, no work or heat can be transferred
• what does internal energy consider?

  changes of heat carried out on a system at a constant volume
• what does enthalpy consider?

  the changes of heat at a constant pressure
• what is the equation for enthalpy?

  H = U + PV
• what is a state function?


  a physical property that depends only on the current state of the system and is independent of the path taken
• why do things dissolve?


  good solvent mimic the surrounding of solute molecules, allowing bonds or ionic attractions to broken and reformed
• what is the enthalpy of solution?

  The heat released or absorbed per mole when a substance dissolves under constant pressure to form a very dilute solution
• is solvation endo or exo thermic?

  Exothermic
• is hydration endo or exo thermic?

  Exothermic
• how to calculate power?


  energy / time
• what is hess's law?


  The standard enthalpy of a reaction is the sum of the standard enthalpies of the reactions into which the overall reaction may be divided
• when to use bomb calorimetry?

  constant volume to measure delta U of combustion reaction
• when to use a solution calorimetry?


  constant pressure method to measure delta H of solution reaction
• what is Cm?


  molar heat capcity
• what are path functions?


  functions whose properties depend on the path taken to reach their specific value

  e.g work and heat
• what is a homogeneous system?


  A system whose properties are the same in all parts, or at least vary continuously from point to point
• what is a heterogeneous system?

  A system consists of two or more distinct homogeneous regions
• what is the van der Waal's equation used for?

  Real gases
• Real gas v ideal gas

  A) Always

  B) Only at low P and high T

  C) zero

  D) small but nonzero

  E) zero

  F) small

  G) zero

  H) small

  
• what type of function is entropy?

  state
• what occurs to the entropy when it changes state from a solid to a liquid?

  positive value
• what would a decrease in disorder mean?

  entropy will be negative
• what occur to the entropy in condensation?


  negative
• what occur to the entropy in dissolving sugar in water?

  positive
• if entropy is positive this is ...

  a spontaneous process
• if gibbs is negative then the reaction is...

  spotaneous
• what type of function is gibbs?

  a state function