#Piranha free

Once the mixture has stabilized, it can be further heated to sustain its reactivity. The 1:1 acid–peroxide mixtures will also create an explosion risk even when using common 30 wt. % hydrogen peroxide.

Solutions made using hydrogen peroxide at concentrations greater than 50 wt % may cause an explosion.

A sudden increase in temperature can also lead to a violent boiling of the extremely acidic solution. It must be allowed to cool reasonably before it is used. Even when made with care, the resulting heat can easily bring the solution temperature above 100 ☌. If the solution is made rapidly, it will instantly boil, releasing large amounts of corrosive fumes. Mixing the solution is an extremely exothermic process. This minimises the concentration of hydrogen peroxide during the mixing process, helping to reduce instantaneous heat generation and explosion risk. Piranha solution should always be prepared by adding hydrogen peroxide to sulfuric acid slowly, never in reverse order. Piranha solution cleans by decomposing organic contaminants, and a large amount of contaminant will cause violent bubbling and a release of gas that can cause an explosion.

#Piranha free

Surfaces must be reasonably clean and completely free of organic solvents from previous washing steps before coming into contact with the solution. It is highly corrosive and an extremely powerful oxidizer. Piranha solution must be prepared with great care. At higher pH, H 2O 2 will decompose violently. 11.6) also accelerates its decomposition. As hydrogen peroxide is less stable at high pH than under acidic conditions, OH (pH c. A closely related mixture, sometimes called 'base piranha', is a 3:1 mixture of ammonia solution ( OH, or NH 3(aq)) with hydrogen peroxide. A typical mixture is 3 parts of concentrated sulfuric acid and 1 part of 30 wt. % hydrogen peroxide solution other protocols may use a 4:1 or even 7:1 mixture. Many different mixture ratios are commonly used, and all are called piranha. This means the solution can also easily dissolve fabric and skin, potentially causing severe damage and chemical burns in case of inadvertent contact. Because the mixture is a strong oxidizing agent, it will decompose most organic matter, and it will also hydroxylate most surfaces (by adding –OH groups), making them highly hydrophilic (water-compatible). The result of the mixture gives rise to a strong union of two acids called per-hexa-sulfuric acid (H 4SO 6) that is used to clean organic residues off substrates. Piranha solution, also known as piranha etch, is a mixture of sulfuric acid ( H 2SO 4) and hydrogen peroxide ( H 2O 2). Molecular models of the different molecules active in Piranha solution: peroxysulfuric acid ( H 2SO 5) and hydrogen peroxide ( H 2O 2).