# Question #68168

Apr 11, 2017

Could be anything, like magnesium powder added to dilute acid, or many others.

#### Explanation:

My bet though, would be on a relatively strong hydrogen peroxide solution ${H}_{2} {O}_{2} \left(a q\right)$, to which manganese dioxide $M n {O}_{2}$ was added. The $M n {O}_{2}$ acts as a catalyst for the following reaction:

$2 {H}_{2} {O}_{2} \left(a q\right) \to 2 {H}_{2} O \left(l\right) + {O}_{2} \left(g\right)$

If you want to make sure you could test for the gas being oxygen (glowing splinter).