DRAFT: This module has unpublished changes.

Driving question: What is the stoichiometric composition of an ionic compound?




The purpose of this lab was to determine the empirical formula of the compound Magnesium Oxide. We used a crucible and bunsen burner to heat the substance until there was no water left in the sample. The average ratio between Magnesium and Oxygen is 1:1 and the average empirical formula is MgO.  The Magnesium and oxygen forming Magnesium Oxide is expressed in this equation:


The chemical equation for the reaction between Magnesium and Oxygen is 




The empirical formula of a compound is the simplest whole number ratio of the elements in the compound.  During the experiment, we found the empirical formula of the compound Magnesium Oxide by synthesizing the elements.


There were three steps taken to find the empirical formula of Magnesium Oxide:


1. The first step was to determine the mass of each element in the compound by heating the sample.


2. After finding the masses, the number of moles of Magnesium and Oxygen were found.


For example: 


if there is 1.57g of Oxygen the formula to find the number of moles would be 



3.  After finding the moles of each element, the molar ratio is expressed as the smallest whole numbers, then the molar ratio is used to find the empirical formula.

DRAFT: This module has unpublished changes.