"100 volume" when referring to hydrogen peroxide (H₂O₂) is a way of expressing its concentration. It doesn't mean the solution is 100% hydrogen peroxide. Here's what it actually means:

* "100 volume" indicates the volume of oxygen gas that would be released from 100 ml of the hydrogen peroxide solution if it were to decompose completely.

Here's the breakdown:

* Decomposition: Hydrogen peroxide decomposes into water (H₂O) and oxygen gas (O₂).

* Reaction: 2 H₂O₂ → 2 H₂O + O₂

* Stoichiometry: The reaction shows that 2 moles of H₂O₂ produce 1 mole of O₂.

Example:

* A "100 volume" hydrogen peroxide solution will release 100 ml of oxygen gas when 100 ml of the solution decomposes.

Important notes:

* "100 volume" is not a standard concentration unit. It's an industry-specific term used mainly in hairdressing and some chemical applications.

* The concentration of a "100 volume" hydrogen peroxide solution is actually around 30% w/w (weight/weight), meaning 30 grams of hydrogen peroxide are dissolved in 100 grams of the solution.

In summary:

"100 volume" is a way of expressing the concentration of hydrogen peroxide by indicating the volume of oxygen gas it will produce when completely decomposed. It's a more practical term in some applications than percentage concentration.