# Laboratory 3. Empirical Formula Of An Oxide

Topics: Mass, Oxygen, Magnesium Pages: 3 (960 words) Published: March 23, 2014
﻿Laboratory 3. Empirical Formula Of An Oxide
This experiment will demonstrate the law of conservation of mass, and more specifically, how the law can be used to experimentally determine the empirical formula of our intended product, magnesium oxide. In this experiment we will learn how to: 1. heat a sample in a crucible with a Bunsen burner.

2. use the method of weight by difference to determine mass quantities. 3. convert grams to moles.
4. determine the simplest ratio between two molar quantities, and to convert the ratio into a chemical formula and finally will be able to gain efficiency in using significant figures properly. METHOD

This experiment will introduce us to new lab equipments that we never used in this lab, a Bunsen burner and a crucible. By chemically reacting Magnesium and Oxygen, we can absolutely calculate the empirical formula of Magnesium Oxide. We measure the mass of the Magnesium initially and the mass of Magnesium Oxide at the end. Then, easily found the difference between Magnesium Oxide and Magnesium to get the ‘mass’ of the Oxygen. This method seemed more beneficial rather than measuring the mass of Oxygen initially. If Magnesium ribbon is being heated in open air, it has very obvious and rapid reaction as the metal meet fire and burns with an intense white flame with the white smoke as a product. The problem while doing this experiment is that there will be other reactions that will occur when we burn the ribbon in an open air. Some of the magnesium oxide formed will be changed to airborne. In order to prevent this loss, we used a closed crucible for combustion. We lifted the cover gently to let small amount of oxygen to the magnesium and let it glow but not burst in to flame. This way, we controlled the rate of the reaction and made sure only little amount of oxide was lost. The crucible must be measured accurately before and after the reaction. At the final experiment, we had to make sure that magnesium only...