If 1.2 moles of CuCl are mixed with
excess of H2S gas, how many moles of Cu2S would be made?

Moles of CuS : 1.2

The reaction coefficient in a chemical equation shows the mole ratio of the components of the reactants and products

If one mole of the reactant or product is known, then we can determine the moles of the other compounds involved in the reaction

Reaction

CuCl₂ (aq) + H₂S (g) → CuS (s) + 2HCl (aq)

CuCl are mixed with  excess of H₂S gas, so CuCl as a limiting reactant

mol ratio of CuCl₂ : mol CuS = 1 : 1, so mol CuS :

answer is: naturally occurring solid, inorganic compound or element is mineral.

minerals usually have crystalline form, that means than crystal constituents (atoms, molecules or ions) are arranged in a highly ordered microscopic structure, forming a crystal lattice that extends in all directions.

for example magnetite is a mineral of iron oxide (fe₂o₃).

calcite is a carbonate mineral and the most stable polymorph of calcium carbonate (caco₃).

dolomite is an   carbonate mineral composed of calcium magnesium carbonate (camg(co₃)₂).