What is Mercuric Chloride Definition Preparation Reactions and Uses
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 HgCl2 Structure Properties and Applications
1. What is mercuric chloride?
**Mercuric chloride** is a highly toxic inorganic compound of mercury with the chemical formula HgCl2. It is also known as **corrosive sublimate** and consists of one mercury(II) ion bonded to two chloride ions. Key points:
- It is a white crystalline solid.
- Mercury is in the +2 oxidation state.
- It is soluble in water and forms a molecular compound.
- It has been historically used as a disinfectant and in laboratories.
2. What is the chemical formula of mercuric chloride?
The chemical formula of **mercuric chloride** is HgCl2. In this compound:
- Mercury has an oxidation state of +2 (Hg2+).
- Each chloride ion has a charge of −1 (Cl−).
- Two chloride ions balance one Hg2+ ion, giving the neutral formula HgCl2.
3. What is the oxidation state of mercury in mercuric chloride?
The oxidation state of mercury in **mercuric chloride (HgCl2)** is +2. This is determined because:
- Each chlorine atom has an oxidation state of −1.
- Total oxidation state of two Cl atoms = −2.
- To make the compound electrically neutral, mercury must be +2.
4. How is mercuric chloride prepared?
**Mercuric chloride (HgCl2)** can be prepared by the direct reaction of mercury with chlorine gas. The balanced chemical equation is:
- Hg(l) + Cl2(g) → HgCl2(s)
- HgO(s) + 2HCl(aq) → HgCl2(aq) + H2O(l)
5. What is the difference between mercuric chloride and mercurous chloride?
The main difference between **mercuric chloride** and **mercurous chloride** is the oxidation state of mercury. Key differences:
- Mercuric chloride: Formula HgCl2, mercury is +2.
- Mercurous chloride: Formula Hg2Cl2, each mercury is +1.
- HgCl2 is more soluble and highly toxic.
- Hg2Cl2 (calomel) is less soluble in water.
6. Is mercuric chloride ionic or covalent?
**Mercuric chloride (HgCl2)** is primarily a **covalent molecular compound** despite containing metal and nonmetal elements. Although it involves Hg2+ and Cl− ions conceptually, the bonding has significant covalent character due to:
- The high polarizing power of Hg2+.
- Fajans’ rules predicting covalent character.
- Its existence as discrete linear molecules in the solid and gaseous states.
7. Why is mercuric chloride highly toxic?
**Mercuric chloride is highly toxic because Hg2+ ions bind strongly to proteins and enzymes in the body.** It reacts with sulfhydryl (–SH) groups in proteins, causing:
- Enzyme inactivation.
- Damage to kidneys and nervous system.
- Severe corrosive effects on tissues.
8. What happens when mercuric chloride reacts with potassium iodide?
When **mercuric chloride reacts with potassium iodide**, a red precipitate of mercury(II) iodide forms. The balanced equation is:
- HgCl2(aq) + 2KI(aq) → HgI2(s) + 2KCl(aq)
9. What are the uses of mercuric chloride in chemistry?
**Mercuric chloride (HgCl2)** has been used in laboratories and industry, although its use is now restricted due to toxicity. Common uses include:
- As a reagent in organic synthesis.
- In qualitative inorganic analysis to detect certain ions.
- Historically as a disinfectant and preservative.
- In wood preservation and fungicides (now largely discontinued).
10. How do you test for mercuric chloride in a laboratory?
**Mercuric chloride can be detected by adding potassium iodide solution to form a red precipitate of HgI2.** The confirmatory reaction is:
- HgCl2(aq) + 2KI(aq) → HgI2(s) + 2KCl(aq)
- The red HgI2 precipitate dissolves in excess KI to form a soluble complex, [HgI4]2−.
