“Determination of the Empirical Formula of an Unknown Lead Oxide”
By: Dr. C. Steven Joiner In this paper, they walk through and explain the process known as smelting. The experiment demonstrates the historical process known as smelting and could theoretically be used to determine the empirical formula of other metal oxides found in nature. This paper explains how the process of smelting and how metals can be extracted from their ores. This is because a few metals can be found in their elemental forms in nature. It explains the process which involves the use of a chemical reaction to isolate the metal in its elemental form from an ionic compound which includes the metal as a salt. Smelting goes
through the process of oxidation-reduction (redox) chemistry. In normal smelting reactions, a sacrificial reducing agent is added to the mineral ore. The reducing agent is oxidized (loses electrons), and the metal cation from the ore gains electrons or becomes reduced. In result this allows the elemental metal to be isolated. During this reaction, it shows that a metal is reduced from a cation with a positive charge to a neutral element, and carbon is oxidized from the neutral element to carbon dioxide. In an experiment, a chemical formula was found by smelting lead oxide to form elemental lead, which results in an unbalanced chemical reaction. The number of moles of lead was determined by measuring the mass of the lead at the end of the experiment. Applying the law of conservation of mass, this allows the number of moles of oxygen that can be calculated. Both of these outcomes, which is the empirical formula, and high possibility of the identity of the sample can be named. Then it leads to the process in which lead oxide can be weighed and heated properly. They also caution and take in to consideration the dangers of the experiment, when working with methane gas, which is highly flammable and dangerous. This ensures that the safety in the care that must be taken to not allow the methane gas to slip from the stopper and to restrict the ignition tube to melt during the experiment, or the methane gas may react and combust. The masses of the powder in the ignition tube of the initial (starting) and the final (ending) are found by subtracting the mass of the ignition tube from the mass of the tube containing the powder. From that the mass that is lost from the heating can be found by subtracting the final or ending mass of the residue, which is presumed to be elemental lead, from the starting or initial mass of the lead oxide. By using the element, which is the mass of residue is assumed to be lead; mass lost upon heating is assumed to be oxygen, this lets us find the number of moles of each element. The mass percent of lead in the sample can be calculated by dividing the mass of the residue, which is assumed to be pure lead) by the mass of the original sample and then multiplying by 100%. By comparing the number of moles of lead to the number of moles of oxygen of each sample this leads to the empirical formula. This experiment successfully identified the unknown lead oxide with the empirical formula. This paper helps to explain the process of smelting to show that metals can be extracted from their ores, which also help us determine the reducing agent and the empirical formula for lead (IV) oxide. This provides that pure samples of minerals composed of metal oxides could be acquired. People can benefit from this paper, for those who do not understand the process of using the empirical formula to find the pure metal. This paper breaks down the process into easy to read step by steps. This paper was in a 2nd person format which was factual and was the most relatable because it was not very biased or opinionated.