Intermediate Topic 683 of 1102 Inorganic Chemistry
Mercury
The only common liquid metal at room temperature, toxic and forming amalgams.
In-depth explanation of Mercury
Mercury is the only metal that is liquid at standard conditions, melting at -38.8 degrees C and boiling at 357 degrees C. Relativistic contraction of the 6s orbitals weakens metallic bonding, which partly explains its liquid state. Mercury forms amalgams, which are alloys with other metals dissolved in it. It forms the mercury(I) ion, Hg2 2+, which contains a metal-metal bond, and the mercury(II) ion. Mercury and its compounds are highly toxic, and organic forms such as methylmercury accumulate in the food chain.
Going deeper: Mercury
Key ideas: Hg is a liquid at room temperature (mp -39 C) due to the relativistic contraction of 6s electrons, giving weak metallic bonding. It forms Hg2 2+ (a Hg-Hg bond, mercurous) and Hg2+. HgCl2 corrosive sublimate is a covalent, linear, weak electrolyte; Hg2Cl2 calomel is white. Disproportion occurs: Hg2 2+ gives Hg + Hg2+. Amalgams dissolve metals (Ag, Au, Na) except Fe. Vapor is toxic, and organomercurials accumulate in the food chain.
Common mistakes and connections: Students think mercurous ion is Hg+; it is the dimer. Treat Hg spills with sulfur powder. Hg is not a typical transition metal, with d10 configuration like Zn and Cd. Chloride test: NH3 added to calomel gives black Hg plus white HgNH2Cl. Links to relativistic effects, disproportionation, amalgam and environmental toxicology.
Visualization of Mercury
Melting points show mercury (234 K) as the only metal liquid at room temperature, far below its neighbours Zn and Cd. The interactive lesson shows this as a live animation or chart.
Worked example and use case
Methylmercury released into water accumulated in fish and caused the Minamata disease epidemic.
Frequently asked questions about Mercury
What is Mercury?
The only common liquid metal at room temperature, toxic and forming amalgams.
Is Mercury a beginner, intermediate or advanced topic?
Mercury is a intermediate topic in Inorganic Chemistry. It builds on the vocabulary of beginner topics in this area.
What should I learn before Mercury?
Study these earlier topics in Inorganic Chemistry first: Potassium Permanganate, Silver Chemistry, Gold and Platinum.
What comes after Mercury?
The next topics in Inorganic Chemistry are Lanthanides and Actinides.
Can I practise Mercury with quizzes?
Yes. The interactive lesson includes a self-check question on Mercury, and the Inorganic Chemistry quiz draws on every topic in this area.
Where Mercury fits in Inorganic Chemistry
Mercury is topic 68 of 113 in Inorganic Chemistry.