Acetylsalicylic acid is an aromatic covalent compound also referred to as Aspirin in the medicinal world. Let us see the different properties of acetylsalicylic acid.
Acetylsalicylic acid is a derivative of salicylic acid, having a planar molecular geometry. It is a white solid crystalline compound that is soluble in acetone, diethyl ether, and ethanol; and weakly soluble in water. Acetylsalicylic acid has a flashpoint of 482⁰F.
Properties like melting point, boiling point, molar density, crystal structure, oxidation state, and reactions of acetylsalicylic acid will be discussed further in this article.
Acetylsalicylic Acid IUPAC Name
The IUPAC Name (International Union of Pure and Applied Chemistry) of acetylsalicylic acid is 2-Acetoxybenzoic acid.
Acetylsalicylic Acid Chemical Formula
The acetylsalicylic acid molecule is denoted by the chemical formula C9H8O4, and its extended form can be written as CH3COOC6H4COOH.
Acetylsalicylic Acid CAS number
The CAS (Chemical Abstract Services) number of Acetylsalicylic acid for verification of the chemical is: 50-78-2.
Acetylsalicylic Acid ChemSpider ID
The ChemSpider ID is 2157 for Acetylsalicylic acid. Each molecule needs its unique ID in order to be identified in ChemSpider.
Acetylsalicylic Acid Chemical Classification
The chemical characteristics of acetylsalicylic acid can be listed as follows:
- An acetylated salicylate, acetylsalicylic acid, is one of the classes of nonsteroidal anti-inflammatory medication.
- Acetylsalicylic acid is categorized as a non-selective cyclooxygenase inhibitor.
- Acetylsalicylic acid (in its powdered form) when coupled with air can be explosive.
Acetylsalicylic Acid Molar mass
The acetylsalicylic acid molecule has a molar mass of 180.158g/mol.
Acetylsalicylic Acid Colour
Acetylsalicylic acid has the appearance of crystalline powder that ranges in colour from colourless to white.
Acetylsalicylic Acid Viscosity
Acetylsalicylic acid is moderately viscous in nature due to the presence of inter-molecular hydrogen bonds attractions.
Acetylsalicylic Acid Molar Density
The molar density of acetylsalicylic acid is 0.0078 mol/cm3 since it has a density of 1.40g/cm3.
Acetylsalicylic Acid Melting Point
Acetylsalicylic acid has a melting point of 136⁰C or 276.8⁰F, and at higher temperatures, it starts to decompose.
Acetylsalicylic Acid Boiling Point
Acetylsalicylic acid has a boiling point of 140⁰C or 284⁰F.
Acetylsalicylic Acid at Room Temperature
At room temperature, acetylsalicylic acid exists in the form of a crystalline white solid.
Acetylsalicylic Acid Covalent Bond
The chemical molecule acetylsalicylic acid is a covalent compound. A serine residue is covalently bound to an acetyl group. Both carbon-carbon double bonds (C=C) and carbon-oxygen double bonds (C=O) are present in acetylsalicylic acid.
Acetylsalicylic Acid Ionic/Covalent Radius
It is not possible to estimate the covalent radius of acetylsalicylic acid like any other compound since the covalent radius can only be computed for a single atom.
Acetylsalicylic Acid Electronic Configurations
Electronic configuration is the arrangement of electrons in orbitals surrounding the nucleus of an atom. Let us check the electronic configuration of acetylsalicylic acid.
The Electronic configurations of Carbon and Oxygen are [He]2s22p2 and [He]2s22p4 respectively. The other atom present in acetylsalicylic acid is hydrogen and its electronic configuration is 1s1. It may be represented for one atom only.
Acetylsalicylic Acid Oxidation State
The average oxidation state of 9 Carbons in acetylsalicylic acid is +0. The 4 Oxygen atoms exist in the oxidation state of -2, and each of the 8 hydrogen atoms is in a +1 oxidation state.
Acetylsalicylic Acid Acidity/Alkaline
Acetylsalicylic acid is a monoprotic weak acid, and its acid dissociation constant (pKa) at 25⁰C (77⁰F) is 3.5.
Is Acetylsalicylic Acid Odourless
Acetylsalicylic acid is odourless in nature, i.e., it emits no smell, although it acquires the odour of vinegar-like acetic acid upon contact with moisture.
Is Acetylsalicylic Acid Paramagnetic
Paramagnetism is caused by a small magnetic field applied to some materials externally. Let us find out whether or not Acetylsalicylic acid is paramagnetic in nature.
Acetylsalicylic acid does not show paramagnetism, instead it is diamagnetic (when placed in a magnetic field, it becomes freely magnetised) in nature as it is an aromatic compound having paired number of electrons in each of their orbitals.
Acetylsalicylic Acid hydrates
Acetylsalicylic acid shows no stable formation of hydrates. Acetylsalicylic acid is poorly soluble in water since the benzene ring present in it is hydrophobic and does not interact with water. Acetylsalicylic acid is generally more soluble in non-polar solvents.
Acetylsalicylic Acid Crystal Structure
The acetylsalicylic acid polymorphism crystallizes in two identical forms: form I and form II. At room temperature, form II changes to form I.
- In form I, two salicylic molecules form centrosymmetric dimers by acetyl and (acidic) methyl proton-carbonyl hydrogen bonds.
- Form II salicylic molecules create the same hydrogen bonds with two neighbouring molecules.
Both polymorphs produce identical dimer structures. This similarity is responsible for the intergrowth structure that contains both form I and form II domains inside the same crystal.
Acetylsalicylic Acid Polarity/Conductivity
- Acetylsalicylic acid has two polar groups: carboxyl and ester group. The two groups connected to a non-polar benzene ring however shows a larger effect than the polar groups in the acid. Thus acetylsalicylic acid is moderately polar in nature.
- Acetylsalicylic acid although covalent in nature conducts electricity poorly.
Acetylsalicylic Acid Reaction with Acid
Acetylsalicylic acid leads to decomposition when reacted with a strong acid like hydrochloric acid. On reaction with dilute hydrochloric acid at 70⁰C, acetylsalicylic acid forms salicylic acid and acetic acid. The reaction is given as follows:
Acetylsalicylic Acid Reaction with Base
Acetylsalicylic acid reacts with a base (for example, Sodium hydroxide in aqueous state) to form the sodium acetylsalicylate salt and water. This reaction is known as acid-base neutralization reaction (General reaction: acid + base —-> salt + water).
Acetylsalicylic acid reacts with a weak base, sodium bicarbonate (NaHCO3), to produce sodium acetylsalicylate salt, Carbon dioxide gas, and water.
Acetylsalicylic Acid Reaction with Oxide
The reaction between Acetylsalicylic acid and oxides does not proceed forward to give any desirable products.
Acetylsalicylic Acid Reaction with Metal
Acetylsalicylic acid reacts with ferrous gluconate in water to form salicylic acid as major product, acetylated gluconic acid, and a salicylate-gluconic acid conjugate. The reaction is given as follows:
Acetylsalicylic acid complexes coordinate to the metal ions via the oxygen in the ester group and oxygen of the carboxyl group. It decomposes easily in alkali metal hydroxides.
Conclusion
Acetylsalicylic acid chemically synthesized from salicylic acid via acetylation with acetic anhydride, has anti–coagulatory and antipyretic properties. It helps prevent venous and arterial thrombosis. Acetylsalicylic acid inhibits cyclooxygenase activity.
Hello, I am Padmakshi Kotoky working as a Subject Matter Expert on this platform. I have completed my post-graduation from the Institute of Chemical Technology, Mumbai. I have always found Chemistry an intriguing subject and enjoy exploring more on it. I would like to utilize this platform to explain the subject in an easy and precise manner making it simpler for the readers to understand the concepts with clarity. I engage myself in Singing, Dancing, and nature photography during my leisure time.
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