Some metals occur naturally in their elemental state while others occur as compounds in ores. Gold, for instance, is found as the free metal; mercury is obtained by heating mercury(II) sulfide ore in oxygen; and zinc is obtained by heating zinc(II) oxide ore with coke (carbon). Judging from their positions in the activity series, which of the metals sil-ver, platinum, and chromium would probably be obtained by (c) heating its oxide with coke?

Verified step by step guidance

1. insert step 1> Identify the metals in question: silver (Ag), platinum (Pt), and chromium (Cr).
2. insert step 2> Recall the activity series of metals, which ranks metals by their reactivity.
3. insert step 3> Understand that metals lower in the activity series are less reactive and can be reduced from their oxides by heating with coke (carbon).
4. insert step 4> Compare the positions of silver, platinum, and chromium in the activity series to determine which is least reactive.
5. insert step 5> Conclude that the metal that is least reactive and can be reduced by heating its oxide with coke is the one that fits the criteria.

Key Concepts

Activity Series of Metals

The activity series is a list of metals arranged in order of decreasing reactivity. More reactive metals can displace less reactive metals from their compounds. Understanding where a metal falls in this series helps predict whether it can be extracted from its oxide using a reducing agent like coke.

Reduction Reactions

Reduction reactions involve the gain of electrons or the removal of oxygen from a substance. In metallurgy, heating an oxide with coke reduces the metal oxide to its elemental form by removing oxygen, allowing the metal to be extracted. This process is crucial for metals that are less reactive.

Metallurgy and Ore Processing

Metallurgy is the science of extracting metals from their ores and refining them for use. Different methods, such as heating with coke or using other reducing agents, are employed based on the metal's reactivity and the nature of the ore. This knowledge is essential for determining the most efficient extraction method for specific metals.