Gravimetric analysis involves either precipitation, which is a traditional old-fashioned method for detecting the mass of compounds in solution or a more modern approach based on thermal gravimetric analysis (TGA). TGA involves heating a sample on a microbalance to determine the mass change as a function of temperature. As the temperature is increased using a constant ramp function thermal decomposition and chemical changes can occur. These are record as mass loss (usually percent mass loss), which can then be converted into atomic units based on the original molecular mass.
Mass data can be used to determine the emipirical formula. The empirical formula tells us only the ratio of the various elements in a molecular compound, but not the overall molecular mass. The next segment concerns how to use both relative and absolute mass determinations to obtain empirical and molecule formulae, respectively.
