Question

The chemical formula of chromite mineral:
A. $FeO.C{r_2}{O_3}$
B. $Fe{S_2}$
C. $ZnS$
D. $A{g_2}S$

Answer 1

Hint: Chromite minerals are mainly found in mafic-ultramafic igneous intrusions and are also sometimes found in the metamorphic rocks. The chromite minerals occur in layered formations that can be hundreds of kilometres long and a few meters thick. Chromite is also very common in iron meteorites and forms in association with silicates and troilite minerals. The chromite mineral consists of iron chromium oxide.

Complete step by step answer:
Chromite is a mineral that is an iron chromium oxide. It has a chemical formula of \[FeC{r_2}{O_4}\] . It is an oxide mineral belonging to the spinel group. Chromite occurs as massive and granular crystals and very rarely as octahedral crystals. Twinning for this mineral occurs on the 3rd plane as described by the spinel law.
The grains of minerals are generally small in size. However, chromite grains up to 3 cm have been found. These grains are seen to crystallize from the liquid of a meteorite body where there are low amounts of chromium and oxygen. The large grains are associated with stable supersaturated conditions seen from the meteorite body. The chromite mineral consists of a simple ration combination of iron (II) oxide and chromium (III) oxide bonded by covalent bonds and various other cohesive forces.

Thus, the correct option is A. $FeO.C{r_2}{O_3}$ .

Note:
Chromite is an important mineral in helping to determine the conditions that rocks form. It can have reactions with various gases such as \[CO\] and \[C{O_2}\]. The reaction between these gases and the solid chromite grains results in the reduction of the chromite and allows for the formation of iron and chromium alloys. There could also be a formation of metal carbides from the interaction with chromite and the gases.