Aluminum metal is produced by passing an electric current through a solution of aluminum oxide \(\left(\mathrm{Al}_{2} \mathrm{O}_{3}\right)\) dissolved in molten cryolite \(\left(\mathrm{Na}_{3} \mathrm{AlF}_{6}\right) .\) Calculate the molar masses of \(\mathrm{Al}_{2} \mathrm{O}_{3}\) and \(\mathrm{Na}_{3} \mathrm{AlF}_{6 \cdot}\).

Aluminum oxide, with the chemical formula \( \mathrm{Al}_{2} \mathrm{O}_{3} \), is a compound composed of aluminum and oxygen. It’s a significant material in various industrial processes, particularly in the production of aluminum metal. During this process, aluminum oxide acts as a source of aluminum. Its characteristics, such as high melting point and electrical resistance, make it suitable for the electrolytic extraction of aluminum.

When calculating its molar mass, we consider the atomic masses of aluminum and oxygen. The equation \( \mathrm{Al}_{2} \mathrm{O}_{3} \) represents that it contains two atoms of aluminum and three atoms of oxygen. Multiplying the atomic mass of each element by its quantity and adding them together provides the molar mass of aluminum oxide.

Molten cryolite, \( \mathrm{Na}_{3} \mathrm{AlF}_{6} \), is a crucial substance used in the Hall-Héroult process for the extraction of aluminum. It serves as a solvent for aluminum oxide at high temperatures, reducing the melting point and improving the efficiency of the process. Without the use of molten cryolite, the extraction process would require substantially higher temperatures and would be less economically feasible.

Cryolite’s unique composition includes sodium, aluminum, and fluorine. To determine the molar mass of molten cryolite, individual atomic masses of these elements are considered. The compound has three sodium atoms, one aluminum atom, and six fluorine atoms, thus its molar mass is calculated by combining the mass contributions from each atom.

The periodic table is an essential tool for chemists and students alike. It organizes all known elements by increasing atomic number, and each element's placement provides valuable information about its properties. Most importantly, in the context of molar mass calculation, the periodic table provides the atomic mass of each element, which is required for calculating the molar mass of compounds.

When faced with the task of finding the molar mass, one starts by locating the elements involved in the compound on the periodic table and noting their respective atomic masses. By having a strong understanding of the layout and information provided by the periodic table, one can quickly and accurately participate in stoichiometric calculations.

Stoichiometry is the branch of chemistry that deals with the quantitative relationships between reactants and products in a chemical reaction. In essence, it involves calculations of molar masses, reaction coefficients, and conversion factors to predict the amounts of substances consumed and produced in reactions.

To use stoichiometry effectively, one must first understand the concept of the mole, which is a unit representing a specific number of particles, typically Avogadro's number. Calculating molar masses, as in our exercise with aluminum oxide and molten cryolite, is a foundational skill in stoichiometry, allowing us to translate between masses of substances and the number of moles, and thus to balance equations and design chemical processes.