在德国和西班牙从朱砂（HgS）中提取汞。

Step-by-Step Solution for the Extraction of Mercury from Cinnabar (HgS)

1. Identify the Ore: The ore of mercury is known as cinnabar, which has the chemical formula HgS (mercury sulfide).

Hint: Remember that cinnabar is a sulfide ore, which means it contains sulfur along with mercury.

2. Roasting Process: The first step in the extraction process is roasting. During roasting, cinnabar (HgS) is heated in the presence of oxygen. This process converts the sulfide ore into an oxide ore.

Hint: Roasting involves heating the ore in the presence of oxygen to facilitate the conversion from sulfide to oxide.

3. Chemical Reaction: The chemical reaction during roasting can be represented as:
        2HgS+3O2→2HgO+2SO2
In this reaction, cinnabar (HgS) is converted into mercury oxide (HgO) and sulfur dioxide (SO₂) gas is released.

Hint: Focus on the reactants and products; sulfur dioxide is a key byproduct of this reaction.

4. Reduction of Mercury Oxide: The next step involves the reduction of mercury oxide (HgO) to obtain mercury metal (Hg). This is typically done by heating mercury oxide.

Hint: Reduction is the process of removing oxygen from a compound to obtain the pure metal.

5. Chemical Reaction for Reduction: The reduction of mercury oxide can be represented as:
2HgO→2Hg+O2
Here, mercury oxide is decomposed into liquid mercury (Hg) and oxygen gas (O₂).

Hint: Remember that the mercury produced is in liquid form due to its low melting point.

6. Properties of Mercury: It is important to note that mercury is unique as it is a liquid at room temperature. Its melting point is below room temperature, and its boiling point is above room temperature.

Hint: Keep in mind the physical state of mercury; it is the only metal that is liquid at room temperature.

Summary
The extraction of mercury from its ore, cinnabar (HgS), involves roasting the ore to convert it into mercury oxide (HgO), followed by reduction to obtain liquid mercury (Hg).