Ammonium carbonate ((NH4)2CO3) is a salt. It forms when ammonia and carbon dioxide react. It has many uses, such as baking and smelling salts.
| IUPAC name | Ammonium carbonate |
| Molecular formula | (NH4)2CO3 |
| CAS number | 506-87-6 |
| Synonyms | baker’s ammonia, sal volatile, salt of hartshorn, E503 |
| InChI | InChI=1S/CH2O3.2H3N/c2-1(3)4;;/h(H2,2,3,4);2*1H3 |
Ammonium Carbonate Properties
Ammonium Carbonate Formula
The chemical formula or molecular formula of ammonium carbonate is (NH4)2CO31. It is a salt that consists of two ammonium ions and one carbonate ion. It can be written as NH4+ + NH4+ + CO3 2- to show the charges of the ions.
Ammonium Carbonate Molar Mass
The molar mass of (NH4)2CO3 is 96.09 g/mol2. To calculate the molar mass, we need to add up the atomic masses of all the atoms in the formula. The atomic masses are:
- Nitrogen: 14.01 g/mol
- Hydrogen: 1.01 g/mol
- Carbon: 12.01 g/mol
- Oxygen: 16.00 g/mol
So, the molar mass of ammonium carbonate is:
(2 x 14.01) + (8 x 1.01) + 12.01 + (3 x 16.00) = 96.09 g/mol
Ammonium Carbonate Boiling Point
(NH4)2CO3 does not have a boiling point because it decomposes before reaching that temperature. When heated, it breaks down into ammonia gas and carbon dioxide gas, which escape from the solid. The decomposition reaction is:
(NH4)2CO3 -> 2 NH3 + CO2 + H2O
The decomposition temperature depends on the humidity and pressure of the environment, but it is usually around 60°C.
Ammonium Carbonate Melting Point
(NH4)2CO3 has a melting point of 58°C (136°F; 331 K). However, it also decomposes at this temperature, so it does not form a liquid phase. Instead, it sublimes directly from solid to gas.
Ammonium Carbonate Density g/ml
The density of (NH4)2CO3 is 1.50 g/ml. Density is the mass per unit volume of a substance. To calculate the density, we need to divide the mass by the volume. For example, if we have 10 g of (NH4)2CO3 and it occupies 6.67 ml of space, then the density is:
10 g / 6.67 ml = 1.50 g/ml
Ammonium Carbonate Molecular Weight
The molecular weight of (NH4)2CO3 is the same as its molar mass, which is 96.09 g/mol. Molecular weight and molar mass are often used interchangeably, but they have slightly different meanings. Molecular weight is the mass of one molecule of a substance, while molar mass is the mass of one mole (6.022 x 10^23 molecules) of a substance.
Ammonium Carbonate Structure
The structure of (NH4)2CO3 can be represented by a Lewis dot structure or a ball-and-stick model. A Lewis dot structure shows the valence electrons of each atom and how they are shared or transferred to form bonds. A ball-and-stick model shows the shape and arrangement of the atoms and bonds in three dimensions.
Here is a possible Lewis dot structure for ammonium carbonate:
O O O
|| || ||
H-N-H H-N-H H-C-H
| | |
H H H
Here is a possible ball-and-stick model for ammonium carbonate:
In this model, each color represents a different element:
- Gray: carbon
- Red: oxygen
- Blue: nitrogen
- White: hydrogen
Ammonium Carbonate Solubility
(NH4)2CO3 is soluble in water. Solubility is the ability of a substance to dissolve in another substance. When (NH4)2CO3 dissolves in water, it forms aqueous ions that can interact with other ions or molecules in solution. The dissolution reaction is:
(NH4)2CO3 + H2O -> 2 NH4+ + CO3 2- + H2O
The solubility of (NH4)2CO3 depends on the temperature and pH of the water. At higher temperatures, more (NH4)2CO3 can dissolve in water.
| Appearance | White powder |
| Specific gravity | 1.50 |
| Color | Colorless |
| Odor | Pungent odor of ammonia |
| Molar mass | 96.09 g/mol |
| Density | 1.50 g/ml |
| Melting point | 58°C (136°F; 331 K) |
| Boiling point | Decomposes before boiling |
| Flash point | Not applicable |
| Water solubility | 100 g/100 ml (15°C) |
| Solubility | Soluble in water, alcohol, and acetone |
| Vapour pressure | Not available |
| Vapour density | Not available |
| pKa | 9.25 (for NH4+) |
| pH | 7.8 (for 0.1 M solution) |
Ammonium Carbonate Safety and Hazards
(NH4)2CO3 is a hazardous substance that can cause irritation and harm to the skin, eyes, nose, throat, and lungs. It can also be harmful if swallowed. It should be handled with care and personal protective equipment, such as gloves, goggles, and masks. It should be stored in a cool, dry, and well-ventilated place, away from heat, sparks, and flames. It should not be mixed with strong acids, bases, or reducing agents, as it may react violently or release toxic gases. In case of exposure, seek medical attention immediately.
| Hazard symbols | Xi (Irritant) |
| Safety description | S22: Do not breathe dust. S24/25: Avoid contact with skin and eyes. |
| UN IDs | UN3077 |
| HS code | 28369910 |
| Hazard class | 9 |
| Packing group | III |
| Toxicity | LD50 oral rat: 2000 mg/kg |
Ammonium Carbonate Synthesis Methods
Different methods can synthesize (NH4)2CO3, depending on what materials they start with and how pure they want the product to be. Here are some examples of (NH4)2CO3 synthesis methods:
- One method is to react ammonium sulfate with ammonium chloride and calcium carbonate in a furnace. The reaction produces (NH4)2CO3 and calcium chloride as by-products. The reaction is:
(NH4)2SO4 + 2 NH4Cl + CaCO3 -> 2 (NH4)2CO3 + CaCl2
- Another method is to react with carbon dioxide and ammonia in an aqueous solution. The reaction produces (NH4)2CO3 and water as by-products. The reaction is:
CO2 + 2 NH3 + H2O -> (NH4)2CO3 + H2O
- A third method is to expose an ammonium solution to air that contains carbon dioxide. Ammonium bicarbonate is the product of the reaction, and heating can further decompose it to (NH4)2CO3.
The reactions are:
NH3 + CO2 + H2O -> NH4HCO3
NH4HCO3 -> NH3 + CO2 + H2O
(NH4)2CO3 -> (NH4)2CO3
- Exposing ammonium bicarbonate to air produces (NH4)2CO3 for commercial use. The ammonium bicarbonate decomposes to ammonia and carbon dioxide, which react again to form (NH4)2CO3. The process is:
NH4HCO3 -> NH3 + CO2
NH3 + CO2 -> (NH4)2CO3
Ammonium Carbonate Uses
(NH4)2CO3 has various uses in different fields, such as:
- Bakers use it as a leavening agent, especially for cookies and crackers that are flat or crispy. It produces carbon dioxide and ammonia gases that help the dough rise and create a light texture. It also enhances the flavor and aroma of baked goods.
- People use it as a smelling salt to revive people who have fainted or are feeling faint. It stimulates the respiratory system and increases blood pressure by releasing ammonia vapors that irritate the nose and lungs.
- Some cough syrups and expectorants, such as Buckley’s cough syrup, use it as an active ingredient. It helps loosen and expel phlegm from the chest and throat by increasing the secretion of mucus.
- Doctors use it as an emetic to induce vomiting in cases of poisoning or overdose. It irritates the stomach lining and causes nausea and vomiting by releasing carbon dioxide gas.
- Chemists use it as a reagent in some chemical reactions, such as the synthesis of urea, ammonium nitrate, and ammonium sulfate. It also acts as a buffer to maintain the pH of solutions.
Questions:
Q: Is ammonium carbonate acidic or basic?
A: (NH4)2CO3 is a salt that can react with both acids and bases. When it dissolves in water, it forms ammonium ions and carbonate ions. The ammonium ions can act as weak acids and donate protons to water, while the carbonate ions can act as weak bases and accept protons from water. The pH of the solution depends on the relative strengths of the ammonium ions and the carbonate ions. If the carbonate ions are stronger bases than the ammonium ions are acids, the solution will be basic. The solution will be acidic if the ammonium ions are stronger acids than the carbonate ions are bases. If the ammonium ions and the carbonate ions have similar strengths, the solution will be neutral.
Q: Is ammonium carbonate a salt?
A: Yes, (NH4)2CO3 is a salt. A salt is a compound that forms when an acid and a base neutralize each other. (NH4)2CO3 can form when ammonia, a weak base, reacts with carbonic acid, a weak acid. The reaction is:
2 NH3 + H2CO3 -> (NH4)2CO3 + H2O
Ammonia and carbonic acid are the parent base and acid of (NH4)2CO3.
Q: Does ammonium carbonate (aq) have an odor in aqueous form?
A: Yes, (NH4)2CO3 (aq) has an odor in aqueous form. The odor is due to the release of ammonia gas from the solution. Ammonia gas has a pungent smell that can irritate the nose and lungs. Ammonia gas can escape from the solution because it is volatile and has a low solubility in water. The amount of ammonia gas released depends on the temperature and concentration of the solution.
Q: What type of atom is ammonium carbonate?
A: (NH4)2CO3 is not an atom, but a molecule. A molecule is a group of atoms that are bonded together by sharing electrons. An atom is the smallest unit of matter that has a defined chemical identity. (NH4)2CO3 is a molecule that consists of four different types of atoms: nitrogen, hydrogen, carbon, and oxygen. The molecular formula of (NH4)2CO3 is (NH4)2CO3.
Q: How many moles are in ammonium carbonate?
A: To answer this question, we need to know how much (NH4)2CO3 we have in terms of mass or volume. A mole is a unit of measurement that represents 6.022 x 10^23 particles of a substance. The number of moles of a substance can be calculated by dividing its mass by its molar mass, or by multiplying its volume by its molarity. The molar mass of (NH4)2CO3 is 96.09 g/mol. The molarity of (NH4)2CO3 depends on how much it is dissolved in water.
For example, if we have 10 g of (NH4)2CO3, we can find the number of moles by dividing 10 g by 96.09 g/mol:
10 g / 96.09 g/mol = 0.104 mol
If we have 100 ml of 0.1 M (NH4)2CO3 solution, we can find the number of moles by multiplying 100 ml by 0.1 mol/L:
100 ml x 0.1 mol/L = 0.01 mol
Q: What is the chemical formula for ammonium carbonate?
A: The chemical formula for ammonium carbonate is (NH4)2CO3. This formula shows that one molecule of (NH4)2CO3 contains two ammonium ions (NH4+) and one carbonate ion (CO3 2-). The charges of the ions balance each other, so the overall charge of the molecule is zero.
Q: How many moles of ammonium ions are in 6.995 g of ammonium carbonate?
A: To answer this question, we need to use two steps:
- First, we need to find how many moles of (NH4)2CO3 are in 6.995 g by dividing 6.995 g by its molar mass (96.09 g/mol):
6.995 g / 96.09 g/mol = 0.0728 mol
- Second, we need to multiply this number by two, because each mole of (NH4)2CO3 contains two moles of ammonium ions:
0.0728 mol x 2 = 0.1456 mol
Therefore, there are 0.1456 moles of ammonium ions in 6.995 g of (NH4)2CO3.
Q: What is the gas produced when hydrochloric acid is reacted with ammonium carbonate?
A: When hydrochloric acid reacts with (NH4)2CO3, they undergo a double-displacement reaction to produce ammonium chloride and carbonic acid. The carbonic acid then decomposes into water and carbon dioxide gas. The carbon dioxide gas is the gas produced by this reaction. The overall equation for this reaction is:
(NH4)2CO3 + 2 HCl -> 2 NH4Cl + H2CO3
H2CO3 -> H2O + CO2
The net ionic equation for this reaction is:
CO3 2- + 2 H+ -> H2O + CO2