The most common source of copper (cu) is the mineral chalcopyrite (cufes2). how many kilograms of chalcopyrite must be mined to obtain 300. g of pure cu?

Answer : 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.

Solution : Given,

Mass of Cu = 300 g

Molar mass of Cu = 63.546 g/mole

Molar mass of = 183.511 g/mole

The moles of Cu = 4.7209 moles

From the given chemical formula, we conclude that the each mole of compound contain one mole of Cu.

So, The moles of Cu = Moles of = 4.4209 moles

Mass of = Moles of × Molar mass of = 4.4209 moles × 183.511 g/mole = 866.337 g

Mass of = 866.337 g = 0.8663 Kg         (1 Kg = 1000 g)

Therefore, 0.8663 Kg of chalcopyrite must be mined to obtained 300 g of pure Cu.

the formula mass of a molecule or a compound is the sum of the atomic weights of the atoms in its empirical formula

(that's what i know about formula mass)