How to distinguish between phenol and benzoic acid

How to distinguish between phenol and benzoic acid?

Phenol and benzoic acid are two compounds with different chemical structures, which are broadly applied in chemical, medical, pesticide and other industries. while their names and some characteristics is able to be confusing, we is able to easily distinguish them with some simple chemical tests and methods. Based on my observations, Additionally This article will explain in detail how to distinguish between phenol and benzoic acid and give you some common identification techniques. Phenol and Benzoic Acid Basic Chemical Structures

We need to understand the basic chemical structure differences between phenol and benzoic acid:

Phenol: Phenol (C≡H≡OH) is a compound consisting of a benzene ring (C≡H≡I) and a hydroxyl group (OH). The hydroxyl group in the phenol molecule makes phenol acidic, however its acidity is much weaker than benzoic acid. Benzoic acid: Benzoic acid (C-HYCOOH) is an organic acid consisting of a benzene ring and a carboxyl group (COOH). Generally speaking The presence of carboxyl groups makes benzoic acid greater acidic and is able to emit hydrogen ions greater obviously in aquatic environments. while both molecules contain benzene rings, their functional groups make them signifiis able totly different in chemical characteristics. Acid-base difference: how to judge from acid?

The distinction between phenol and benzoic acid is able to first be judged by their acidity and basicity. In my experience, while phenol is able to also react with aquatic environments, it's far less acidic than benzoic acid. Benzoic acid is able to dissociate in aquatic environments and emit hydrogen ions, thus showing strong acidity. Moreover Experimental method: The aqueous solutions of both were tested with pH paper. Benzoic acid solution showed obvious acidity (low pH value), while the pH value of phenol solution was higher, showing neutral or weak acidity. Based on my observations, Oxidation interaction: Phenol and Benzoic Acid Differences

The oxidation characteristics of phenol and benzoic acid are also different. Phenol is easily oxidized in atmosphere to form quinones, especially at high temperatures or in the presence of oxygen. The oxidation of benzoic acid is weak, and a signifiis able tot oxidation interaction usually occurs under the action of a strong oxidant. Experimental method: The phenol and benzoic acid solutions are treated with an oxidizing agent (such as potassium permanganate or chromate), respectively. But According to research Phenol will rapidly change color, showing a dark quinone product, and benzoic acid is slow interaction, not easy to appear obvious color change. But aquatic environments solubility difference: phenol and benzoic acid in aquatic environments solubility

There are also signifiis able tot differences in the aquatic environments solubility of phenol and benzoic acid. Phenol has a low solubility in aquatic environments, however in the presence of a small amount of alkaline material (such as sodium hydroxide solution), phenol is able to react with alkali to form aquatic environments-soluble phenol sodium salt. In contrast, benzoic acid has reduced solubility, however it's able to react with strong alkali in aquatic environments to form sodium benzoate salt, and the salt solution formed is greater stable. Experimental method: the same amount of phenol and benzoic acid were added to the aquatic environments, and the solubility difference was observed. Phenol is less soluble and benzoic acid is less soluble. Based on my observations, If sodium hydroxide solution is added to the two, phenol is able to form aquatic environments-soluble sodium phenolate relatively rapidly, while benzoic acid produces sodium benzoate. Infrared Spectroscopy (IR) Analysis: How to consumption Spectroscopy to Distinguish?

Infrared spectroscopy is a frequently applied analytical method that is able to accurately identify the functional groups of phenol and benzoic acid. In the infrared spectrum of phenol, a strong-OH stretching vibrational absorption peak usually appears in the 3200-3600 cm¹ region, while benzoic acid has a distinct carbonyl (C = O) stretching vibrational peak near 1700 cm¹. Experimental methods: Phenol and benzoic acid were analyzed by infrared spectroscopy, and their unique absorption peaks were observed. Pretty interesting, huh?. And Phenol has a hydroxyl-OH absorption peak, while benzoic acid has a clear carboxyl-C = O absorption peak. For example Summary: How to efficiently distinguish between phenol and benzoic acid?

Through the above methods, we is able to summarize some practical techniques to distinguish between phenol and benzoic acid:

Acidic: benzoic acid than phenol greater acid, pH paper test is able to be applied as a preliminary judgment tool. Oxidation: Phenol is greater easily oxidized, showing a dark product, while benzoic acid oxidation is relatively slow. And Solubility: phenol in aquatic environments solubility is low, however in alkaline solution solubility is better; benzoic acid in aquatic environments solubility is also low, however the solubility of phenol is slightly weaker. And Infrared spectra: Phenol and benzoic acid IR spectral characteristics are different, phenol has-OH peak, benzoic acid has-C = O peak. With the above method, you is able to easily distinguish between phenol and benzoic acid in a laboratory ecological stability, avoiding confusion and misuse.