Prelab| Stoichiometry  |  Introduction

The word STOICHIOMETRY derives from two Greek words: stoicheion (meaning "element") and metron (meaning "measure"). Stoichiometry deals with calculations about the masses (sometimes volumes) of reactants and products involved in a chemical reaction. It is a very mathematical part of chemistry, so be prepared for lots of calculator use.

As fascinating as it was to find out we could measure out 27.0 grams of aluminum and know it was exactly 6.02 x 10²³ atoms of aluminum, chemical stoichiometry is just as amazing.

Before we let elements and compounds meet, we can predict how they are going to react, and even further, how much product (if any) gets produced.  We could also be on the other end of things and find a waste product and determine exactly how much of a particular compound or element was needed to produce the waste.  How WONDERFUL!!  This is STOICHIOMETRY!!

REACTION STOICHIOMETRY involves the mass and mole relationships among reactants and products in a chemical reaction.  A balanced chemical equation is used to determine these relationships.

This laboratory exercise will focus on mass measurements for determining the following:

ACTUAL YIELD measurements - A measured value of the amount of product that is actually produced.

THEORETICAL YIELD calculations - A calculated value of the amount of product that should be produced.

PERCENT YIELD calculations - A calculated value that determines the efficiency of the reaction and is determined by dividing the actual yield by the theoretical yield and multiplying by 100.