Hydrogen Peroxide

By Nicolas Fan

Chemical Name

The name for this chemical is hydrogen peroxide, however the correct name is actually Dihydrogen Dioxide. This is because the organization that comes up with the chemical names was established in 1919. They came up with the system known as IUPAC nomenclature which is what we use to name compounds today. Hydrogen Peroxide was discovered 1818 and was named by the current system around at that time. The peroxide comes from the oxygen-oxygen single bond. Therefore, Hydrogen Peroxide is what most people call it, however the correct/systematic name is Dihydrogen Dioxide.

Chemical Formula

As mentioned above the correct systematic name for hydrogen peroxide is dihydrogen dioxide. This explains the chemical formula for this molecular compound. Since the prefixes of di- are on hydrogen and oxygen it means they have 2 atoms in the compound. Therefore, the formula is H2O2.

Compound Structure

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The structure of hydrogen peroxide is seen above. Hydrogens share there electrons with each oxygen atom giving them a full shell. The oxygen atoms also share two electrons between them giving them full valence shells. The two oxygens have 2 lone pair electrons left over which contributes to the shape. The left over electrons repel the bonds because the bonds contain electrons. Therefore the bonds are as far away from the left over electrons that they can be, giving it the shape that you see.

Compound Type

Hydrogen Peroxide is a molecular compound because it contains 2 non-metals. Also the electro-negativity of hydrogen peroxide is 1.24 which makes it a covalent compound. The shape of hydrogen peroxide is bent because each hydrogen needs to bond with an oxygen and the oxygens also need to bond together. This would give you a linear shape, however because the oxygens atoms have 2 lone pair electrons the bonds must repel from the left over electrons. This gives it a bent shape. This means that hydrogen peroxide is polar because it has a region of unequal sharing. The top part where the hydrogens are located (white atoms in picture) have a slight positive charge because its electronegativity is lower then the oxygen atoms (red atoms in picture) electronegativity. Therefore the hydrogen atoms on the top are slightly positive and the oxygen atoms at the bottom are slightly negative. The shape of hydrogen peroxide is always changing. However in whatever shape it is in, there is always an end of partial negativity which can attract the partial positive end of another compound. This means that it is polar.

Common Uses

A diluted hydrogen peroxide solution (3% or less) has many uses in todays society. It is commonly used to to whiten clothes or hair as an alternative to bleach. It removes your old hair colour, while the peroxide lightens the hair through oxidation. Our body also makes hydrogen peroxide to help our immune system fight infections. It is used in mouthwash, toothpaste and tooth whitening, however cannot be digested, just rinsed out with water. It is used for hair lightening, in the dishwasher, to remove stains, to wash stains, to sanitize meat, and finally soak vegetables. As you can see, hydrogen peroxide has many uses in our daily lives, and without it our lives would be much more difficult.


Physical Properties:

State: Hydrogen peroxide is a clear, colourless, odourless liquid. Similar to H2O, hydrogen bonding forms strong intermolecular hydrogen bonding. These strong hydrogen bonding makes it a liquid. It is also aqueous since it has hydrogen atoms, making it a weak acid. Most of the time, we encounter hydrogen peroxide mixed with water as an aqueous solution.

Melting Point: -0.43°C. Although it may seem like this is a low melting point, it is actually very high for a covalent compound. This is because even though it shares its electrons, the bonding type for hydrogen peroxide is hydrogen bonding, which is the strongest type. This makes it harder to melt compared to other covalent compounds.

Boiling Point: 150.2°C. The intermolecular force for hydrogen peroxide is hydrogen bonding. This is the strongest type so therefore, it takes a great deal of energy to break them down. This is why the boiling point is so high.

Chemical Properties:

Flammability: Hydrogen peroxide is not flammable, however it does support combustion because of the hydrogen and oxygen atoms in it. When mixed with oxygen gas, hydrogen peroxide immediately breaks down into carbon dioxide and water vapour. This is why it was used in rocket fuel and torpedo engines.

Toxicity: Hydrogen peroxide is not considered to be toxic, however it can be very dangerous. It can severely injure delicate tissue. It should not be inhaled or digested as it is a very dangerous oxidizer which increases oxygen levels available to the substance.

Benefits of Hydrogen Peroxide

Based on the common uses of hydrogen peroxide, you can see that it has many benefits that help us in our daily lives. One of its main benefits is its ability to disinfect minor cuts and treat infections. Recently, their has been controversy about the use of this chemical on open wounds (as you will see in next section). When hydrogen peroxide comes into contact with an open wound it foams. This is because the blood and cells contain catalase. When catalase mixes with hydrogen peroxide it turns into water and hydrogen gas. The foaming you see is pure oxygen bubbles. Hydrogen peroxide is most successful when dealing with degenerate diseases caused by lack of oxygen and harmful micro-organisms such as asthma, cancer, and other chronic fatigue. It helps through a process called oxidation which is when the compounds oxygen atoms are reactive and attract electrons. Bacteria then becomes weak and breaks apart, allowing oxygen atoms to treat the areas with a lack of oxygen. It is great for cleaning areas of your body such as your teeth, and it can even help you clean stains, clothes, and even the food that you eat. However, hydrogen peroxide can be a very dangerous chemical so it is vital that you take the correct amount. Diluted solutions of hydrogen peroxide are often used in daily lives, and concentrated solutions of 3% or higher can be harmful to your health

Costs to human health

If not used properly hydrogen peroxide can have many negative effects on your body, especially concentrated solutions of 3% or higher. According to many health experts, hydrogen peroxide should only be used on skin and should not be digested. Hydrogen peroxide contains too much oxygen for the blood leading to many issues. It reduces the amount of fibreblasts, a cell that it imperative for cleaning and repairing damaged tissue. Many people think that using hydrogen peroxide to heal wounds is safe but it is not. Hydrogen peroxide kills the surface layer of tissue on the wound so the wound cannot "close" properly. Concentrated solutions of hydrogen peroxide can severely damage tissue in your body. It can also burn your vocal tract of inhaled. Concentrated solutions of this chemical are very dangerous, and can have a severe affect on your health.

Environmental Impact

Hydrogen peroxide is present in surface water, where it exists naturally. As soon as it comes into contact with water, it is broken down into water and oxygen, which have no environmental concerns. It can be harmful to some organisms but it does not bioaccumulate because it just turns into water and oxygen. Hydrogen peroxide is present in the air and water naturally in very low, harmless concentrations. Hydrogen peroxide does not have a huge impact on the environment it can easily be broken down into harmless, naturally occurring elements.

Suggestions for safe use

Hydrogen peroxide should be restricted to its original container and if removed from its original container should not be returned. In case of accidental spillage, hydrogen peroxide will not burn however it should be thoroughly flushed in the spot of the spill. Hydrogen peroxides decomposition liberates oxygen which supports combustion. When it is mixed with other materials that contain catalysts, it can cause rapid decomposition and an explosive pressure rupture of the containing vessel. Safety goggle should always be worn when handling hydrogen peroxide. If it does get in eyes flush eyes thoroughly and consult a physician as it can be irritating and burn corneas. Rubber gloves and suitable protective wearing should also be warn when handling concentrated amounts. If inhaled hydrogen peroxide vapours can cause irritation to the respiratory tract and fresh air should be sought immediately. Diluted solutions of hydrogen peroxide are frequently used in and around your skin and mouth, however concentrated solutions can be very harmful. In regards to an antiseptic, an alternative that you could use instead of hydrogen peroxide is isopropyl alcohol. When using hydrogen peroxide, safety always comes first, and you should familiarize yourself with it for safe and proper handling.