Silver carbonate is a very reactive and unstable chemical compound that you can identify in chemical equations using the silver carbonate formula: Ag2CO3. Fetizon’s reagent often earns mention when it comes to silver carbonate because the reagent is silver carbonate mixed with celite. When you precipitate a silver nitrate solution with an alkaline carbonate, a white mass forms, which, when washed, turns yellow as the soluble salts separate. This product, which you get, is silver carbonate or Ag2CO3. Another important point and defining characteristic of Ag2CO3 is that it is sensitive to light. Under the influence of photochromic light, it changes color.
Silver Carbonate Structure: What Is The Chemical Geometry Of Ag2CO3?
Here you can see the Ag2CO3 structure. The bonds formed in this compound are a result of various factors, the key being: the molecular mass of silver carbonate. The atoms arrange themselves in the manner shown below to attain stability. Yet, silver carbonate is a pretty unstable compound. We will get into those discussions eventually. We will also know more about the properties like the molecular weight of silver carbonate, its reactivity, etc. However, right now, we will look into the silver carbonate structure:
Properties Of Silver Carbonate
The silver carbonate formula is Ag2CO3.
The IUPAC name of Ag2CO3 is Disilver Carbonate.
The density of the compound is 6.08 g/cm3.
The molecular mass of silver carbonate or the molecular weight of silver carbonate is 275.7453 g/mol.
The boiling point of the compound is 553.2-degree centigrade.
The melting point of the compound is 218-degree centigrade.
What Are The Physical Properties Of Silver Carbonate?
Silver carbonate is odorless.
It appears as pale-yellow crystals.
The hydrogen bond acceptor value for the compound is 3.
When it comes to solubility, it is very sparsely soluble in water.
What Are The Chemical Properties Of Silver Carbonate?
Like most other carbonates, our compound here undergoes decomposition, which means it breaks down into simpler constituent reagents from the silver carbonate formula. In the case of silver carbonate, we obtain silver, carbon dioxide, and oxygen. Since the molecular weight of silver is highest in these three, it forms in most amounts.
Ag2CO3 -> Ag2O + CO2
2Ag2O -> 4Ag + O2
Silver carbonate dissolves in nitric acid to form silver nitrate, carbon dioxide and water.
Ag2CO3 + HNO3 -> AgNO3 + H2O + CO2
Uses Of Silver Carbonate: What Are The Uses Of Ag2CO3?
Fetizon’s reagent originates from supporting silver carbonate on celite. This reagent is then applicable in the oxidation of primary and secondary alcohols, which yield aldehydes and ketones, respectively.
It acts as a reagent in a very crucial organic synthesis reaction named Koenig’s – Knorr reaction.
It acts as a base in another significant name reaction: Wittig reaction.
Owing to its high alkynophilicity and basicity, it is essential in many organic transformations, such as the conversion of alkyl bromides to alcohol.
The compound is crucial in the electronics industry, yielding silver, which is very important in chips and microprocessors.
Solved Examples On Silver Carbonate
When you strongly heat 2.76g of silver carbonate, the residue you obtain weighs:
2.16g
2.48g
2.32g
2.64g
Answer:
The reaction involved is as follows:
Ag2CO3 -> 2Ag + CO2 + ½ O2
276g of Ag2CO3 will give 2x108=216g of residue.
Therefore, 2.76g of Ag2CO3 gives 2.16g of silver residue.
Fun Facts
Silver carbonate reacts with ammonia to give a very reactive mass known as fulminating silver.
Although theoretically, the color of silver carbonate is supposed to be yellow, lab samples typically appear greyish. These samples are rich in silver.
Silver carbonate plays a crucial role in microelectronics. It helps in the generation of silver powder, which is used extensively in the chip industry.
Silver carbonate has superior alkynophilicity and basicity, which makes it an ideal catalyst in several organic reactions.
Silver carbonate on celite is neutral, but they form a reagent which is very active in reactions.
FAQs on Silver Carbonate
1. What is silver carbonate and what are its key physical properties?
Silver carbonate, with the chemical formula Ag₂CO₃, is an inorganic compound. It is a light-sensitive, light yellow or beige powder at room temperature. Its key physical properties include a molar mass of approximately 275.75 g/mol and a high melting point, at which it decomposes before melting. It is also odourless and has a very low solubility in water.
2. Why is the chemical formula for silver carbonate written as Ag₂CO₃?
The formula Ag₂CO₃ is determined by the ionic charges of its constituent ions. The silver ion (Ag) typically has a +1 charge, while the carbonate polyatomic ion (CO₃) has a -2 charge. To form a neutral compound, two silver ions are required to balance the single -2 charge of the carbonate ion. Therefore, the formula is correctly written as Ag₂CO₃.
3. How is silver carbonate typically prepared?
Silver carbonate is commonly prepared through a precipitation reaction. This is achieved by mixing aqueous solutions of a soluble silver salt, like silver nitrate (AgNO₃), with a soluble carbonate salt, such as sodium carbonate (Na₂CO₃). The silver carbonate, being insoluble in water, precipitates out as a solid. The net ionic equation for this reaction is: 2Ag⁺(aq) + CO₃²⁻(aq) → Ag₂CO₃(s).
4. What happens when silver carbonate is heated?
When silver carbonate is heated to its decomposition temperature (around 218 °C), it undergoes thermal decomposition. This process breaks down the compound into metallic silver, carbon dioxide gas, and oxygen gas. The balanced chemical equation for this reaction is: 2Ag₂CO₃(s) → 4Ag(s) + 2CO₂(g) + O₂(g). This reaction is an example of the thermal instability of many heavy metal carbonates.
5. What are the important uses of silver carbonate in chemistry?
Silver carbonate serves as a valuable reagent, particularly in organic chemistry. Its primary uses include:
- As a mild oxidizing agent in the synthesis of lactones from diols.
- It forms the basis of Fetizon's reagent (silver carbonate on celite), used to oxidize primary and secondary alcohols.
- It acts as a base in reactions like the Wittig reaction.
- It is used in the Koenigs-Knorr reaction for synthesising glycosides.
6. Why is silver carbonate considered sparingly soluble in water, unlike sodium carbonate?
The difference in solubility is explained by general solubility rules in chemistry. While most carbonate salts are insoluble, those of Group 1 elements (like sodium carbonate, Na₂CO₃) are notable exceptions and are highly soluble. Silver, a transition metal, does not follow this rule. The strong electrostatic forces between the Ag⁺ and CO₃²⁻ ions in the crystal lattice are not easily overcome by the hydration energy of water molecules, leading to its very low solubility, making it sparingly soluble or effectively insoluble for most practical purposes.
7. How does silver carbonate function in Fetizon's reagent?
In Fetizon's reagent, silver carbonate is adsorbed onto the surface of celite (a form of diatomaceous earth). This combination creates a highly effective and selective mild oxidizing agent. The large surface area provided by celite allows for efficient reaction with alcohols. It selectively oxidizes primary and secondary alcohols to aldehydes and ketones, respectively, without affecting other sensitive functional groups, which is a key advantage in complex organic syntheses.
8. Is Ag₂CO₃ considered a precipitate?
Yes, Ag₂CO₃ is considered a precipitate. A precipitate is an insoluble solid that emerges from a liquid solution. Due to its very low solubility in water, when aqueous solutions containing silver ions (Ag⁺) and carbonate ions (CO₃²⁻) are mixed, silver carbonate is formed and immediately separates from the solution as a solid precipitate, typically appearing as a pale yellow powder.
