Closed-Ended Algorithm


  1. Write out the problem statement.
    Include information on what you
    are to solve, and consider why you
    need to solve the problem.



  1. Make sure you are solving the real
    problem as opposed to the perceived
    problem. Use techniques such as "Finding out
    Where the Problem Came From," "The Duncker
    Diagram," "The Explore Phase," etc. to check to
    see that you define and solve the real
    . Recast the problem statement if



  1. Draw and label a sketch.
    Define and name all variables
    and/or symbols. Show numerical
    values of variables if known.



  1. Identify and name
    1. Relevent principles, theories and equations
    2. Systems and subsytems
    3. Dependent and independent variables
    4. Knowns and unknowns
    5. Inputs and outputs
    6. Necessary (missing) information



  1. List assumptions and approximations
    involved in solving the problem.
    Question the assumptions and then
    state which ones are the most reasonable
    for your purposes.



  1. Check to see if the problem is either
    under-specified or over-specified. If
    it is under-specified, figure out how
    to find the missing information. If
    over-specified, identify the extra
    information that isn't needed.



  1. Relate problem to a similar problem
    or experience (compare to an example
    problem in lecture or in the book).



  1. Use an algorithm (e.g. reaction engineering)


    1. Mole Balance
    2. Rate Laws
      1. Kinetic
      2. Transport

    3. Stoichiometry
      1. Gas or liquid
      2. Pressure drop

    4. Combine
    5. Energy Balance
    6. Evaluate


  1. Develop/derive/integrate and/or
    manipulate an equation or equations
    from which the desired variable can
    be determined.



  1. Substitute numerical values and
    calculate the desired variable.
    Check your units at each step in
    the solution to find possible



  1. Examine and evaluate the
    answer to see it makes sense.
    Is it reasonable, considering
    the problem statement? Does it
    consider safety and ethical



See how this algorithm can be applied to Examples in Chemical Reaction Engineering.

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