Question

Argentite is an ore of:
A.Iron
B.Gold
C.Platinum
D.Silver

Answer 1

Hint: Ores are basically the raw materials for making metals. Basically, most of the metals are too reactive and they cannot exist on their own. So, that’s why they are combined with other elements known as ores. Moreover, very few metals such as noble metals such as Gold, platinum etc. are present in their original form.

Complete step by step answer:
Basically, an element may combine with a variety of elements to make minerals but out of them only few are viable sources of that metal and such sources are known as ores. Moreover, metallurgy is the field of science which deals with the extraction of metals from ores which are naturally found in the environment.
Now, let’s talk about the extraction of metals. Basically, the process of extracting metal ores that are buried deep underground is called Mining. The metal ores are found in the Earth’s crust in varying abundance. However, the extraction of metals from ores is what allows us to use the minerals in the ground. Further, the ores consist of the desired metal compound and the impurities called Gauge.
So moving further, Argentite is an ore of silver. It is a cubic silver sulfide \[(A{g_{_2}}S)\] which can only exists at temperatures above ${173^ \circ }C,{177^ \circ }C$ or ${179^ \circ }C$ .Further, when it cools to ordinary temperature, it turns into its monoclinic polymorph known as acanthite. Argentite being sulphide ore is concentrated by the froth flotation process. Basically, the pulverized ore is kept in a large tank containing water and pine oil. The mixture is then distributed by passing compressed air where ore forms the froth with pine oil and comes to the surface while the impurities are left in the water. Further, the concentrated ore is treated with aqueous solution of sodium cyanide. Further, the argentite ore dissolves in sodium cyanide forming sodium argento cyanide. The equation is as shown:
 $A{g_2}S + NaCN \to 2Na[Ag{(CN)_2}] + NO{}_2S$
Now, the solution is filtered and the filtrate containing sodium argento cyanide is used to recover silver metal.

Hence, option D is correct.

Note:
Argentite mineral has aesthetic value and is precious because of its scarcity. It is an effective means of reducing toxicity in the contaminated soils but now The International Mineralogy Association has decided to reject argentite as a proper mineral.