Essential Characteristics and Applications of Mercuric Chloride
Mercuric II Chloride
Mercury and chlorine are the two chemical compounds that react together to form HgCl₂ with the chemical name Mercuric chloride. Mercury chloride is also referred to as Mercury ii chloride or Mercury (II) chloride or Dichlor Mercury. Mercury (II) chloride is a compound that is highly toxic and the compound is also corrosive to the mucous membranes. The compound is mostly used as a wood preservative, disinfectant, fungicide, and antiseptic. By colour, Mercury dichloride is white and odourless in smell. It is a crystalline solid. Mercury ii chloride consists of a mercury atom that is bonded with two chlorines due to which is known as a triatomic molecule. The molecule gets dissolved in water.
Mercuric Chloride (HgCl₂) Properties
Following are some of the properties of mercury chloride:-
The chemical formula of mercuric chloride is HgCl₂.
The molecular weight of the mercuric chloride (HgCl₂) is 271.52 g/mol.
Mercuric chloride has a density of 5.43 g/cm3.
The boiling point of the mercury chloride (HgCl₂) is 304°C.
The melting point of the mercury chloride (HgCl₂) is 276°C.
At ordinary temperatures, mercuric chloride is slightly volatile.
Mercuric chloride is a compound that can be sublime unchanged.
The solubility of the mercury chloride (HgCl₂) is 5 to 10 my/ml.
When inhaled, absorbed by skin or either digest the compound (Mercuric chloride) cause toxicity.
Structure of Mercury Chloride (HgCl₂)
Both the exact mass of the Mercury II Chloride and also the monoisotopic mass of the mercury chloride is 271.908 g/mol. Both the number of donors and the acceptors of the number of hydrogen bonds is equal to zero. This compound consists of only one covalently bonded unit and the compound is canonicalized.
Uses of Mercury Chloride (HgCl₂)
Following are the certain uses of mercury chloride (HgCl₂):-
In the preservation of the anatomical specimens, mercuric chloride is used.
Mercuric chloride is also used in leather tanning.
It is also used in antiseptic and disinfectants.
Mercuric chloride is also used for micrography, in the manufacturing of ink.
In analytical chemistry, this compound is used as a reagent.
This compound is used as an intensifier in photography.
This compound is used in the conversion of acetylene into vinyl chloride as a catalyst.
Mercuric chloride is used as an ant repellent.
Mercuric chloride is used in the cases of the dry battery.
Mercuric chloride solution is used as a dip for tubers and bulbs.
For the conversion of vinyl chloride from acetylene, mercuric chloride is generally used. This vinyl chloride is used as a precursor of polyvinyl chloride.
Occasionally, To form an amalgam of metals such as aluminium, mercuric chloride (HgCl₂) is used.
Mercuric chloride (HgCl₂) is a compound that is also used as a stabilizing agent in both the analytical samples as well as the chemical samples.
FAQs on Mercuric Chloride: Properties, Structure, and Uses
1. What is mercuric chloride and what is its chemical formula?
Mercuric chloride is an inorganic chemical compound with the formula HgCl₂. It is a white, crystalline solid and a highly toxic compound of mercury. Historically, it was known as corrosive sublimate and was used as a disinfectant, though this practice is now obsolete due to its toxicity.
2. How is mercuric chloride typically prepared?
Mercuric chloride can be prepared through several methods. The most common way is by the direct action of chlorine gas on hot mercury. It can also be produced by heating a mixture of solid mercury(II) sulfate and sodium chloride. The volatile HgCl₂ sublimes and can be collected as crystals. The reaction is: HgSO₄ + 2NaCl → HgCl₂ + Na₂SO₄.
3. What are the main uses of mercuric chloride?
Despite its toxicity, mercuric chloride has several specific applications in industry and laboratories. Its primary uses include:
- As a catalyst for converting acetylene into vinyl chloride, a precursor to PVC plastic.
- As a laboratory reagent, for instance, in preparing Nessler's reagent to detect ammonia.
- In photography, it is sometimes used as a photographic intensifier to enhance images.
- As a depolarizer in batteries.
4. What is the key difference between mercuric chloride (HgCl₂) and mercurous chloride (Hg₂Cl₂)?
The main differences lie in the oxidation state of mercury and their resulting properties. In mercuric chloride (HgCl₂), mercury has a +2 oxidation state, making it soluble in water and extremely toxic. In contrast, mercurous chloride (Hg₂Cl₂), also known as calomel, contains mercury in a +1 oxidation state. It is poorly soluble in water and significantly less toxic than HgCl₂.
5. Why is mercuric chloride considered so dangerous?
Mercuric chloride is extremely dangerous primarily because it is a highly corrosive and toxic substance. It can cause severe damage to the body upon contact, ingestion, or inhalation. The toxicity stems from the mercury ion (Hg²⁺), which can damage the kidneys, stomach, and intestines, and disrupt the central nervous system by interfering with essential enzymes.
6. How does mercuric chloride react with ammonia solution?
When mercuric chloride solution is treated with an excess of ammonia solution, it forms a white precipitate. This precipitate is a compound called aminomercuric(II) chloride, also known as 'infusible white precipitate'. The chemical equation for this reaction is: HgCl₂ + 2NH₃ → Hg(NH₂)Cl + NH₄Cl.
7. What is the molecular geometry of mercuric chloride?
In the gaseous state, mercuric chloride exists as a discrete triatomic molecule. It has a linear molecular geometry, with the two chlorine atoms positioned on opposite sides of the central mercury atom, resulting in a Cl-Hg-Cl bond angle of 180°. This shape is predicted by VSEPR theory for a central atom with two bonding pairs and no lone pairs of electrons.
8. Why has the use of mercuric chloride in medicine been discontinued?
The use of mercuric chloride in medicine, such as an antiseptic or treatment for syphilis, was stopped due to its severe toxicity and harmful side effects. Even in small doses, it can cause acute kidney failure and neurological damage. Safer and more effective alternatives, like antibiotics and modern antiseptics, have completely replaced it in medical applications.
