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Unit 7: Stoichiometry

The law of conservation of mass is the corner stone chemistry and the basis of this unit. Here we will learn how to predict the amount of product produced, or the amount of each reactant we will need.
Your instructor will likely teach dimensional analysis (factor label method) in class. However there are a myriad of of ways to do these problems. If one does not work for you ask your instructor for one of the other options, or run through YouTube for more. This is usually a difficult unit for students, so stay in class for as long as possible, and stay after with your teacher to get extra help as often as possible. 


After a short review we begin unit 7, stoichiometry, with the mole to mole ratio. Here we use the balanced equation to determine the amount of reactant or product produced in a reaction 


The second day of unit 7 saw us doing actual stoichiometric calculations. The primary method to do this is the factor label method we learned in unit 1. Make sure you know how to convert between moles and mass! 
The factor label isn't for everyone. While it is the primary method to carry out stoichiometric calculations, there are may ways to do these calculations. Here are two alternatives, however a quick word of warning: while I will accept these methods, please know that they are not a norm. Meaning that you will need to check with YOUR instructor before utilizing them on an assessment.


Mass to mass stoichiometric problems are most common, however you can do them with any unit provided you can determine the number of moles you have. In this lesson we talked about the molar volume of a gas at standard temperature and pressure. 

The quiz in this unit was the following class. For the quiz you were asked to:
 Balance a reaction
 Perform a mass to mass conversion
 Perform two mass to volume conversions
 Calculate an experiments percent yield

The final lecture of unit 7 deals with limiting reagent. In lab you have a finite amount of each reactant, so naturally one will be used up before the other. In this video we discuss determining which will limit the amount of product you can form. 