5HCl

5HCl refers to hydrochloric acid in a solution where the concentration is 5% by mass. Hydrochloric acid is a strong, corrosive mineral acid with the chemical formula HCl. In aqueous solution, it dissociates completely into hydrogen ions (H+) and chloride ions (Cl-). A 5% solution is considered relatively dilute compared to more concentrated forms.

This concentration of hydrochloric acid is commonly used in various industrial, laboratory, and household applications. Industrially, it can be used for pickling steel to remove rust and scale, in the production of other chemicals, and for pH control. In laboratories, it's a standard reagent for titrations, acid-base reactions, and as a solvent. In households, dilute hydrochloric acid can sometimes be found in cleaning products, particularly for removing mineral deposits like limescale or rust, though its use requires caution due to its corrosive nature.

When handling 5% hydrochloric acid, appropriate safety precautions are still necessary. It can cause irritation and burns upon contact with skin and eyes, and its fumes can irritate the respiratory system. Therefore, wearing protective gloves, eye protection, and working in a well-ventilated area are recommended. Despite being a dilute solution, its acidic properties mean it should be handled with respect.