Question

Which of the following is a halide ore?
A: Cassiterite
B: Anglesite
C: Siderite
D: Carnallite

Answer 1

Hint: A halide refers to a binary phase, in which one part belongs to a halogen atom while the other part belongs to an element or radical (that is either less electronegative or more electropositive) in comparison to the halogen. The alkali metals usually combine directly with the halogens to form halides having a general formula, \[MX\](where \[X{\text{ }} = {\text{ }}F,{\text{ }}Br,{\text{ }}Cl,{\text{ }}or{\text{ }}I\]).

Complete answer:
Halide ores refer to the minerals in which metals are connected with halogens. For instance Rock salt i.e. \[NaCl\], Carnallite i.e. \[KCl.MgC{l_2}.6{H_2}O\], Sylvine i.e.\[KCl\], Horn Silver i.e. \[AgCl\].
Option A i.e. Cassiterite, also called as tinstone is heavy, metallic, tin dioxide (i.e. \[Sn{O_2}\]), is considered to be the major ore of tin. It is commercially present in placer deposits, and also in granite or pegmatites. Thus, Cassiterite is not a halide ore.
Option B i.e. Anglesite is a mineral of lead sulphate having the chemical formula of . It exists as an oxidation product of the primary lead sulfide ore i.e. galena. It is present in the form of prismatic orthorhombic crystals or earthy masses. Thus, Anglesite is not a halide ore.
Option C: Siderite is an iron mineral mainly composed of iron(II) carbonate with formula \[FeC{O_3}\]. It is generally used as an iron ore. Thus, Siderite is also not a halide ore.
Option D: Carnallite is actually an evaporite mineral or we can say a hydrated potassium magnesium chloride having a formula \[KCl.MgC{l_2}.6{H_2}O\]. It is generally present in the upper layers of marine salt deposits. Thus, Carnallite is a halide ore.

Hence, the correct answer is Option D.

Note: Carnalite is mostly utilised in fertilizers. It is considered to be a significant source of potash. Soluble potassium salts are the main source for fertilizers.