Density of Pyrite Crystals and Stoichiometric Calculations

Density Calculation:

To find the density of pyrite, given the mass of the pyrite crystals and their dimensions, we use the formula density = mass/volume. The volume of a cube is calculated by raising the length of one side to the third power (since all sides are equal). So, the volume of a pyrite crystal that measures 2 cm on each side is 2 cm x 2 cm x 2 cm = 8 cm³. With a mass of 52 g, we then divide the mass by the volume to obtain the density. Thus, the density = 52 g / 8 cm³ = 6.5 g/cm³.

Stoichiometric Calculations for BaSO₄:

Given that pyrite is approximately 90-95% w/w FeS₂, and we need to ensure obtaining at least 1.0 g of BaSO₄ from the oxidation and precipitation process, we would work out the necessary sample size based on the percent composition and stoichiometry of the relevant reactions. Although the exact calculations are not given, we know that the reactions will follow the conversion from FeS₂ to SO₂ and then to BaSO₄. To determine the sample size, the molar mass of FeS₂, the molar mass of BaSO₄, and the percent purity of the pyrite should be taken into account in stoichiometric calculations.