**Stoichiometry Mastery
Exams**

The Stoichiometry Mastery Exam must be passed at the **85%
level or better**. It deals with equations and
manipulations of chemical algebra based on the various
conservation laws and definitions that introduce the course. The
Exam is offered six times during the course. It __must be
completed successfully to obtain a passing grade__ in the
course if a passing grade is otherwise justified by performance
on exams, homeworks and quizzes. But the Mastery Exam score is
not otherwise factored into the grade calculation. If the Mastery
Exam requirement is not satisfied, the entire course must be
repeated. (You do not receive an "incomplete" grade if
all that remains is the Mastery Exam.) The types of calculations
that can appear on the Exam are drawn from the following
categories (which can serve as a preparation guide):

atomic weights | balancing equations |

molecular weights | reaction yields |

isotopic composition | limiting reagents* |

moles | combustion reactions |

percent composition | mixtures* |

empirical formulas | density |

molecular formulas | dilution problems |

*HINTS:From a number of years of experience with
difficulties some students have in dealing with the
Stoichiometry Mastery Exams, I have concluded that there
is a small subset of pitfalls that can be avoided by
paying attention to the following hints. Learn to
recognize
i.) a limiting reagent problem, and ii.) a mixture
problem. For For the Also, in an equation such as that for oxidizing ethane
2C |