Question

Carnallite is an ore of which of the following metals?
(A) K and Mg
(B) K and Al
(C) Na and K
(D) Na, K, and Al

Answer 1

Hint: An ore is a naturally occurring substance in the deep down earth. It can be identified from its chemical formula. Carnallite is known as potassium magnesium chloride.

Complete step by step answer:
* Firstly, let us know about the ore. An ore is a naturally occurring solid that consists of metals that can be extracted.
* There are many metals having their ores. We can see numerous examples like Cinnabar is an ore of mercury, Borax is an ore of sodium, etc.
* Carnallite is an ore having chemical formula, KMgCl$_3$.6H$_2$O. It can also be written as KCl.MgCl$_2$.6H$_2$O.
* From the chemical formula, we can know about the metals present in an ore.
* Carnallite is having potassium (K) and magnesium (Mg) in its chemical formula, so these metals are present in an ore.
* It is also known as hydrated potassium magnesium chloride as it contains water molecules too.
We can say that carnallite is an ore of potassium and magnesium. So, the correct option is A.

Additional information:
Carnalite is a soft, and white halide mineral. The potassium content is more in it. So, it is identified under the ores of potassium.

Note: Don’t be confused between the chemical formulas. From the chemical name of carnalite, write the formula and identify the metals present in it. Carnallite is a hydrated ore so water molecules should be represented in chemical formula.