The ore weighing 200 g contains the mineral fluorspar CaF2, the raw material for the production

The ore weighing 200 g contains the mineral fluorspar CaF2, the raw material for the production of fluorine. the mass fraction of CaF2 in the ore is 78%. Calculate the mass of fluorine contained in this sample.

Let’s find the mass of calcium fluoride contained in the mineral.

m (CaF2) = 200 * 0.78 = 156 g

To calculate the mass of fluorine, we find the number of moles of fluorine ions in calcium fluoride weighing 156 g. First, we need to calculate the number of moles of calcium fluoride.

M (CaF2) = 78.1 g / mol

n (CaF2) = m / M = 156 / 78.1 = 2 mol

1 mol of CaF2 contains 1 mol of calcium ions and 2 mol of fluorine ions, which means that in an ore sample containing 2 mol of CaF2 (or 156 g of CaF2):

n (Ca) = 2 mol;

n (F) = 2 * 2 = 4 mol.

M (F) = 19.0 g / mol

m (F) = n (F) * M (F) = 4 * 19.0 = 76 g