Copper Dichloride

Introduction

Copper (II) chloride is a compound with a chemical formula called $\mathrm{CuCl_{2}}$. It is one of the compounds found in rare minerals like eriochalcite and tolbachite in its dehydrated or anhydrous form. It is also often found in fumaroles. The two forms of anhydrous (dry powder) or dehydrate (moisten) $\mathrm{CuCl_{2}}$ impart two different colours - yellowish-brown and bluish-green.

This compound acts as a catalyst in chemical synthesis. Another name for this compound or inorganic salt is Cupric chloride.

What is Copper (II) Chloride?

Copper (II) chloride is an inorganic compound with the chemical formula $\mathrm{CuCl_{2}}$. Exist in rare minerals like eriochalcite and tolbachite in the form of dehydrated or anhydrous. The anhydrous form of $\mathrm{CuCl_{2}}$ is yellowish-brown in colour. The dehydrated form of

$\mathrm{CuCl_{2}}$ is blue-green. The oxidation state of the metal (𝐶𝑢) in $\mathrm{CuCl_{2}}$ is +2.

Basic information on copper (II) chloride -

• It is non-combustible. Sometimes, release irritating hydrogen chloride gas when heated.

• It is corrosive to aluminium.

• It shows acidic behaviour in water. $\mathrm{CuCl_{2}}$ is acidic in its solution. The reason is that copper chloride solution results from the neutralization reaction of copper hydroxide and hydrochloric acid. It is the salt of a reaction between a weak base and strong acid, making an aqueous solution of copper chloride slightly acidic. Also, the presence of adequate hydrogen ions in the solution and a pH of fewer than 7 makes $\mathrm{CuCl_{2}}$ acidic in water.

Properties of copper (II) chloride

physical properties include −

S.no	Physical Properties	Values
1.	Molecular weight (anhydrous)	134.45 g/mol
2.	Boiling point	993 0C
3.	Melting point	498 0C
4.	Density	3.386 g/cm3
5.	Odour	No odour

Chemical properties include:

$\mathrm{CuCl_{2}}$ can produce a wide variety of reactions as it is a versatile salt. Therefore it is widely used in many chemical syntheses in our chemical industry. For example-

• Copper (II) chloride undergoes a redox reaction when a reductant is present. The formed compounds comprise cuprous salt and metallic copper.

$$\mathrm{2CuCl_{2}\:+\:SO_{2}\:+\:2H_{2}O\rightarrow\:2CuCl\:+\:2HCL\:+\:H_{2}SO_{4}}$$

• Copper (II) chloride reacts with a base and gives copper (II) hydroxide and sodium chloride.

$$\mathrm{2CuCl_{2}\:+\:2NaOH\rightarrow\:Cu(OH)_{2}\:+\:2NaCl}$$

Copper (II) Chloride Structure

The formula of $\mathrm{CuCl_{2}}$ consists of one cation (𝐶𝑢2+) and two anions (𝐶𝑙−). It has a distorted octahedron structure in its dehydrated form ($\mathrm{CuCl_{2}}$. $\mathrm{2H_{2}O}$), where copper metal is bonded by two water ligands and four chlorine ligands. Though one can represent its structure with its simple representation by 2D representation or Lewis structure of $\mathrm{CuCl_{2}}$.

$\mathrm{CuCl_{2}}$ is an example of an ionic compound. Ionic compounds transfer electrons when they bond. Here is the electron transfer representation- When positive and negative ions are attracted to form an ionic bond. The structure will look like this −

Copper (II) Chloride Uses

• It helps deodorize the petroleum industry.

• It acts as a catalyst for organic and inorganic reactions

• It acts as an oxidizing agent.

• It applies to water treatment.

• It is a fixer on photography.

• It is applicable in the manufacturing of agricultural chemicals.

• It acts as a purifying agent.

• It acts as a mordant in dyeing

• It acts as a disinfectant.

• Applicable for laundry marking inks.

Production of Copper (II) Chloride

• Powder or anhydrous form of $\mathrm{CuCl_{2}}$ is the natural form of combining elements copper and chlorine.

• Dehydrated $\mathrm{CuCl_{2}}$ is produced by carrying out various reactions-

• Chlorination of copper

$$\mathrm{Cu\:Cl_{2}\:+\:2H_{2}O\rightarrow\:CuCl_{2}\:.\:2(H_{2}0)}$$

• Reaction of copper (II) oxide and hydrochloric acid,

$$\mathrm{CuO(s)\:+\:2HCL(aq.)\rightarrow\:CuCl_{2}\:(aq.)+\:H_{2}O(l)}$$

• Reaction of copper (II) hydroxide and $\mathrm{HCl}$

$$\mathrm{Cu(OH)_{2}\:+\:HCL(aq)\rightarrow\:CuCl_{2}\:+\:H_{2}O}$$

• Reaction of copper (II) carbonate and $\mathrm{HCl}$

$$\mathrm{CuCO_{3}\:+\:HCL(aq)\rightarrow\:CuCl_{2}\:+\:CO_{2}\:+\:H_{2}O}$$

Health hazards

• Consuming cupric dichloride causes stomach aches, causing salivation, nausea, vomiting, and diarrhoea.

• Smelling cupric dichloride can irritate the throat, nose, and lungs, further leading to coughing and sneezing.

• Cupric dichloride irritates the eyes and skin when the reagent comes into contact

• Inhaling copper dichloride damages the liver and kidneys.

Conclusion

Copper (II) chloride is a chemical compound with a chemical formula $\mathrm{CuCl_{2}}$. It is also known as cupric chloride. Its dry form is a yellowish-brown powder, and its moistened state turns yellowish-brown to greenish-blue. It is a versatile salt used for many chemical syntheses. Though it is beneficial, it has some health hazards. This harmful compound needs to be used carefully as inhaling such reagents can irritate the nose, lungs, and throat, further leading to coughing, and contact can irritate the skin, eyes, and stomach, causing diarrhoea, nausea, salivation, vomiting, and stomach ache.

FAQs

1. . Find the oxidation state of Cu metal in the compound $\mathrm{CuCl_{2}}$?

In the compound, $\mathrm{CuCl_{2}}$, the overall charge is zero. Therefore, the oxidation state of Cu can be found with the oxidation state formula. Let the charge on Cu be 𝑥 and the charge on Cl is −1.

$$\mathrm{CuCl_{2}\Longrightarrow\:x\:+\:2(-1)\:=\:0}$$

$$\mathrm{\Longrightarrow\:x\:-\:2\:=\:0}$$

$$\mathrm{\Longrightarrow\:x\:=\:2}$$

The charge on Cu is +2.

2. What happens when zinc reacts to 𝑪𝒖𝑪𝒍𝟐?

The reaction is as follows −

$$\mathrm{CuCl_{2}\:+\:Zn\:\rightarrow\:ZnCl_{2}\:+\:Cu}$$

In the above reaction, metal zinc is oxidized to $\mathrm{Zn^{2+}}$, whereas $\mathrm{Cu^{2+}}$ (as cupric chloride) is reduced to copper metal. When zinc metal is put inside into a blue solution of $\mathrm{CuCl_{2}}$, it acquires a copper coating, making the blue colour of the solution fade and precipitating copper.

3. What happens when 𝑪𝒖𝑪𝒍𝟐 reacts to 𝑵𝒂𝑶𝑯?

When copper chloride and sodium hydroxide react, it forms copper hydroxide (blue precipitate) and sodium chloride (white precipitate).

Reaction − $\mathrm{CuCl_{2}\:+\:NaOH\rightarrow\:Cu(OH)_{2}\:+\:NaCl}$

4. Why does 𝑪𝒖𝑪𝒍𝟐 dissolve in water?

The polarity of water molecules makes ionic compounds like $\mathrm{CuCl_{2}}$ dissolve in the water.

5. What happens when a chemical reaction between a piece of zinc and an aqueous solution of cupric chloride takes place? Give the type of reaction with reason.

When a piece of zinc is added to an aqueous solution of cupric chloride, it forms zinc chloride and copper. The reaction is as follows-

$$\mathrm{Zn\:+\:CuCl_{2}\rightarrow\:ZnCl_{2}\:+\:Cu}$$

In the given reaction, both oxidation and reduction take place.

At oxidation − $\mathrm{Zn\rightarrow\:Zn^{2+}\:+\:2e^{-}}$ At reduction $\mathrm{Cu^{2+}\:+\:2e^{-}\rightarrow\:Cu}$ Therefore, it is a redox reaction.