Reaction of the breakdown of hydrogen peroxide and its features

Properties of hydroperite aka perhydrol

[Deposit Photos]

Hy­dro­gen per­ox­ide is an un­sta­ble sub­stance. In pure form, it is un­sta­ble, and eas­i­ly breaks down, with the process of­ten be­ing ac­com­pa­nied by an ex­plo­sion. In wa­ter so­lu­tions, it is more sta­ble, but oxy­gen is con­stant­ly re­leased when the so­lu­tions are stored. This process ac­cel­er­ates from the ef­fect of light, cat­alyz­ers or from heat­ing. Cat­a­lysts can be com­pounds of iron, cop­per, man­ganese diox­ide, cobalt, cata­lase en­zymes and oth­er sub­stances

The chem­i­cal char­ac­ter­is­tics of hy­dro­gen per­ox­ide

Hy­dro­gen per­ox­ide is a trans­par­ent, col­or­less and slight­ly vis­cous liq­uid with­out taste or smell, which in large vol­umes has a bluish tinge. The sub­stance is also known as hy­droperite and per­hy­drol. It is 1.5 times heav­ier than wa­ter and can mix with it in any ra­tios. The molec­u­lar weight of hy­dro­gen per­ox­ide is 34.02, freez­ing point is 0.5 de­grees Cel­sius, and boil­ing point is 67 de­grees. The chem­i­cal for­mu­la is Н₂О₂.

Hy­dro­gen per­ox­ide is a non-com­bustible liq­uid that is fire- and ex­plo­sion-haz­ardous, and a strong ox­i­diz­er which en­ters into re­ac­tions with many sub­stances: hy­dro­gen per­ox­ide eas­i­ly breaks down into oxy­gen and wa­ter when ex­posed to light, and also when it comes into con­tact with re­duc­ing and ox­i­diz­ing sub­stances, in in­ter­ac­tion with an al­ka­line or on heat­ing. In ide­al con­di­tions, Н₂О₂ breaks down slow­ly, with a speed of 1% per month. The speed of break­down slows down in the cold, so the sub­stance can be stored for a long time in a frozen state - from mi­nus 0.5 de­grees Cel­sius. In na­ture, Н₂О₂ is en­coun­tered in in­signif­i­cant quan­ti­ties – for ex­am­ple, in snow or rain­wa­ter.

Molecular structure of hydrogen peroxide [Deposit Photos]

The break­down of hy­dro­gen per­ox­ide — the re­ac­tion in the lab­o­ra­to­ry

The cat­alyt­ic break­down of hy­dro­gen per­ox­ide in this ex­per­i­ment looks very ef­fec­tive. Take a con­ic flask with a ca­pac­i­ty of 300 ml, and pour 15 ml of dish­wash­ing liq­uid of any brand into it. In an­oth­er flask, dis­solve 4 grams of cop­per sul­fate with plen­ty of strong am­mo­ni­um so­lu­tion – add the so­lu­tion un­til the cop­per sul­fate dis­solves com­plete­ly. Blue cop­per am­mine forms in the re­ac­tion.

Pour the cop­per am­mine so­lu­tion into the flask with the dish­wash­ing liq­uid and mix thor­ough­ly. Then place the flask on a ta­ble and quick­ly add 70 ml of a 30-50% so­lu­tion of hy­dro­gen per­ox­ide. A large amount of gas is re­leased, and a foun­tain of foam spurts from the flask. The en­tire work space is cov­ered with large clumps of foam. As the re­ac­tion of break­down of hy­dro­gen per­ox­ide takes place with re­lease of heat, steam ris­es from the foam.


30-50% hy­dro­gen per­ox­ide can be re­placed with hy­dro­gen per­ox­ide so­lu­tion that is sold in phar­ma­cies. To make sure that the break­down of hy­dro­gen per­ox­ide takes place quick­ly, we rec­om­mend that you use a high con­cen­tra­tion of H₂O₂. On the oth­er hand, the cat­a­lyst of the break­down of H₂O₂ should be quite ac­tive — you can use cop­per am­mine or potas­si­um per­man­ganate. Some­times potas­si­um io­dide is used, but ex­per­i­ments with this sub­stance are not al­ways suc­cess­ful.

Warn­ing! Don’t try to re­peat this ex­per­i­ment with­out a pro­fes­sion­al su­per­vi­sion! We rec­om­mend you to do a safe, but in the same time amaz­ing ex­per­i­ment — “Egyp­tian night”.

Study­ing the re­ac­tion of the break­down of hy­dro­gen per­ox­ide

Liq­uid hy­dro­gen per­ox­ide has greater en­er­gy than liq­uid wa­ter and gaseous oxy­gen by 23 kcal, i.e. it breaks down exother­mi­cal­ly. Liq­uid Н₂О₂ re­leas­es 13 kcal in the re­ac­tion of the break­down into oxy­gen and wa­ter va­por. Us­ing sim­ple arith­metic, we can eas­i­ly cal­cu­late that when one cu­bic cen­time­ter of pure liq­uid hy­dro­gen per­ox­ide breaks down into oxy­gen and wa­ter, self-heat­ing takes place so that all the wa­ter moves to a va­porous state, and the re­sult­ing mix­ture of gaseous oxy­gen and wa­ter mol­e­cules reach­es a tem­per­a­ture of around 1000 de­grees Cel­sius.


As a re­sult of the in­crease in tem­per­a­ture, the gas­es ex­pand, and 1 cm of liq­uid hy­dro­gen per­ox­ide gives 7000 cm of hot gas­es when it breaks down. As the break­down takes place in­stan­ta­neous­ly with an ex­pan­sion of 7000 times, there is a very dan­ger­ous ex­plo­sion. As soon as a small amount of this hy­dro­gen per­ox­ide breaks down, the sub­stances re­leased in the break­down heat the neigh­bor­ing par­ti­cles of hy­dro­gen per­ox­ide, which in their turn break down from heat­ing, re­lease more heat, and so on. The re­ac­tion that starts in one point or small drop of hy­dro­gen per­ox­ide im­me­di­ate­ly spreads through­out the en­tire mass of the sub­stance, and an ex­plo­sion takes place, and in the pres­ence of com­bustible sub­stances, there is a flash.

For ex­am­ple, even a 60% so­lu­tion of hy­dro­gen per­ox­ide at room tem­per­a­ture ig­nites wood chips and pa­per on con­tact with them. The low­er the con­cen­tra­tion of hy­dro­gen per­ox­ide, the less dan­ger­ous it is, as the heat from the chem­i­cal re­ac­tion of the break­down goes to­wards the evap­o­ra­tion of a large mass of wa­ter, which has con­sid­er­able ther­mal ca­pac­i­ty and heat of evap­o­ra­tion. It is clear that a 10% so­lu­tion of hy­dro­gen per­ox­ide can heat it­self up to boil­ing tem­per­a­ture on break­ing down, and even a 3% so­lu­tion of hy­dro­gen per­ox­ide down can heat it­self up 20 de­grees above its ini­tial tem­per­a­ture when it breaks down.

If con­cen­trat­ed hy­dro­gen per­ox­ide is se­vere­ly con­tam­i­nat­ed, the break­down re­ac­tion may ac­cel­er­ate, be­cause of the self-heat­ing of the sub­stance. This process, which is slow at first, may reach an ex­treme speed, ac­com­pa­nied by the ex­plo­sion of the con­tain­er, de­spite the pres­ence of a vent. Pos­si­ble ac­ci­dents can be pre­vent­ed by con­stant­ly rais­ing the tem­per­a­ture of the prod­uct over a cer­tain pe­ri­od of time. The speed of the in­crease in tem­per­a­ture is the func­tion of the de­gree of con­tam­i­na­tion. If the heat­ing is not stopped, the con­tam­i­nat­ed hy­dro­gen per­ox­ide should be quick­ly di­lut­ed with wa­ter and poured away. Large reser­voirs for stor­ing con­cen­trat­ed hy­dro­gen per­ox­ide should be equipped with ther­mome­ters, in or­der to pro­vide warn­ings of a pos­si­ble break­down.