Citric acid is available in natural form in several fruits and vegetables. Still, most notably, you can taste their presence in citrus fruits like lemons and lime that contain a high volume of citric acid. It might take you by surprise, but Citric acid can take up to 8% of the fruit's total dry weight.
The first isolation of Citric acid took place in 1784 by the chemist named Carl Wilhelm Scheele, who experimented by crystallizing it from lemon juice. Citric acid is present in two forms in nature. One is the water free form, which is called anhydrous, and the other one is monohydrate. However, in both forms, the chemical name, and the Citric acid structure remains the same.
On the other hand, Citric acid's isolation on an industrial scale first took place in 1890 in Italy. As the citrus fruit company used hydrated lime, which is Calcium hydroxide, to precipitate Calcium citrate in the juice. The Calcium Citrate was being isolated and got converted back to acid, which then gets diluted by
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(Citric acid's structural representation.)
Citric acid is said to be a tribasic acid. As a result, if you want to prepare acidic salts of Citric acid, you can do it by carefully balancing pH before the compound's crystallization starts to occur. One of the examples of acidic salts derived from this acid is Sodium citrate.
The Citric acid chemical formula is C6H8O7. In its naturally occurring form, the Citric acid crystals have white colour, which you can also find on the top of sour candies.
Preparation of Citric Acid
You can get Citric acid from the market as it is a weak acid. You do not need to have a special order to buy it from a local chemical store. If you want to prepare it by yourself, you need to follow the given steps.
Step 1:- First, you need to have lemons, and we mean lots of lemons. You need 450 ml of lemon juice to extract a good amount of crystallized Citric acid. Test the lemon juice by using a pH strip. The result should be around 2 or 3 pH scale.
Step 2:- Add a little bit of eyedrop, which contains 10% strength Sodium hydroxide, and test the solution again. Now take the coffee filter and pour down the solution into another glass. Also, at this stage, check for any solid particles in the solution that you poured into a new flask.
Step 3:- Now put 28 grams of Calcium Chloride to 70 ml of distilled water and combine both the solutions in one glass and heat it.
Step 4:- Again, filter out the solution using a coffee filter to get calcium citrate out of it. Now, as the Calcium citrate is taken out, mix it with heavily diluted sulfuric acid, and then stir it. Filter out the solution with water, and store the citric acid in a beaker.
Step 5:- Heat the solution on medium heat so the water gets evaporated from the beaker. Finally, filter out the Citric acid and let it cool down in a bowl.
Properties of Citric Acid
We have already discussed the structure of Citric Acid. Now, let us move to citric acid's properties. The citric acid common name is citrate, and the systematic IUPAC name of Citric acid is 2-Hydroxypropane-1,2,3-tricarboxylic acid.
The Citric acid density is 1.66 g/cm³. The density is one of the important properties of any chemical compound as it defines how much of it can mix in any particular substance. The molecular weight of Citric acid, which is present in the monohydrate form, is 210.14 g/mol.
Uses of Citric Acids in Daily Life
There are several ways in which Citric Acid benefits humankind. Below are some of the major uses.
First, in beverages, Citric acid provides tartness and enhances the fruits and berries flavours. Also, with its addition, the antimicrobial preservatives get a boost, and it provides adjustments in pH to give uniform acidity to the soft drinks.
In frozen fruits, Citric acid makes pH to go lower to make oxidative enzymes inactive.
In pharmaceuticals, this acid works as an effervescent combined with bicarbonates to provide rapid dissolution of active ingredients.