Sphalerite, a sulphide mineral with the formula ZnS, is an important ore of which metal?

Introduction / Context:
Sphalerite is one of the major ore minerals discussed in introductory chemistry and geology courses. It is a sulphide mineral that contains a metal of industrial importance used for galvanising iron, making alloys, and producing various chemicals. This question asks you to identify which metal is obtained from sphalerite. A firm grasp of common ore names and their associated metals is useful for both science and general knowledge examinations.

Given Data / Assumptions:
- The ore in question is sphalerite, known to have the chemical formula ZnS.
- Four metals are listed as possible answers: zinc, mercury, molybdenum, and silver.
- The task is to select the metal for which sphalerite is an important ore.
- Standard information from school level mineralogy tables is assumed.

Concept / Approach:
Sphalerite is zinc sulphide, ZnS, and is the most important ore of zinc. The name sphalerite comes from a Greek word meaning deceptive, because it can be mistaken for other minerals, but its composition is clearly dominated by zinc. Mercury is commonly obtained from cinnabar, HgS. Molybdenum comes from molybdenite, MoS2. Silver is mined from ores such as argentite and other silver bearing minerals. Therefore sphalerite is specifically associated with zinc, not with the other metals listed.

Step-by-Step Solution:
Step 1: Recall that sphalerite has the chemical formula ZnS, indicating the presence of zinc and sulphur. Step 2: Recognise that Zn is the chemical symbol for zinc in the periodic table. Step 3: Understand that zinc is extracted from sphalerite by roasting the sulphide and then reducing the resulting oxide. Step 4: Compare with mercury, which is obtained from cinnabar, HgS, not from sphalerite. Step 5: Compare with molybdenum, obtained from molybdenite, MoS2, and with silver from argentite and related ores. Step 6: Conclude that zinc is the metal associated with sphalerite as an important ore.

Verification / Alternative check:
Chemistry textbooks typically include a table of important metals and their chief ores. Sphalerite is always listed as zinc sulphide and as a principal zinc ore, often alongside other zinc minerals like calamine. The same tables do not list sphalerite under mercury, molybdenum, or silver. Geology references further describe sphalerite as occurring in hydrothermal veins and sedimentary rocks, again in the context of zinc mining. This consistent classification across sources confirms that zinc is the correct answer.

Why Other Options Are Wrong:
Mercury: Extracted mainly from cinnabar, HgS, not from sphalerite, which contains zinc instead of mercury.
Molybdenum: Obtained from molybdenite, MoS2, and associated ores, not from sphalerite.
Silver: Mined from argentite and other silver rich minerals, rather than from zinc sulphide ores such as sphalerite.

Common Pitfalls:
One common error is to associate any sulphide mineral vaguely with multiple metals without recalling the specific formulas. Learners may also confuse sphalerite with galena, another sulphide ore but of lead. Paying close attention to chemical formulas helps. When you see ZnS, you should immediately think of zinc sulphide and therefore zinc as the extracted metal. Building a small mental list of key ore mineral pairs, like sphalerite zinc, cinnabar mercury, and bauxite aluminium, makes such questions straightforward.

Final Answer:
Sphalerite, ZnS, is an important ore of Zinc, which is extracted from this mineral for use in galvanising, alloy production, and various chemical industries.