It is very common to hear people recommend some cola-based soft drinks to unclog sinks. But does it really work?
Do not. Contrary to popular sayings, cola-based soft drinks are not used to unclog sinks.
So where did this idea come from?
Well, these cola-based soft drinks (tree of the sterculiaceous family, whose seed contains alkaloids) contain in their structure an acid called orthophosphoric acid, which is best known for phosphoric acid (H3DUST4). This acid is a colorless solid commercially available, usually in the form of a viscous liquid. The purpose of its use in soft drinks is to give the drink an acidic taste, so it acts as an acidulant. It also acts as a preservative, that is, it keeps the product in good condition (to be consumed for longer) and increases the perception of sweet taste.
Confusion arises because this compound is also used by industry for other purposes, such as in the pharmaceutical industry, in the preparation of fertilizers, in anti-rust products and in cleaning supplies
. However, the concentrations and proportions in which phosphoric acid solutions are used in each of these cases are totally different.
In the case of cola-type soft drinks, there is usually 0.6 g of phosphoric acid for each liter of solution. The commercial concentrated phosphoric acid, called xxaporous phosphoric acid, is an aqueous solution containing 85% by mass of this acid.
There is no need to worry either, because phosphoric acid is not harmful to humans; even, in chemical reactions that occur in our cells to supply cellular energy, phosphates are used (PO4-3), which are components of phosphoric acid.
However, this does not mean that you can consume as much of these drinks as you like without harming your health. The excess can indeed be harmful, as the phosphate can react with the calcium present in our bones and teeth, leading to weakening of these parts of the body, even causing osteoporosis, with time.
So the next time your sink or toilet clogs, you're better off using a sink cleaner than wasting several liters of soda.
By Jennifer Fogaça
Graduated in Chemistry
Source: Brazil School - https://brasilescola.uol.com.br/quimica/refrigerante-base-cola-desentope-pia.htm
