The Role of Chemistry in History

Introduction – Discovery – How is it Made?

Uses 1 – Uses 2 – Uses 3

Hydrogen Peroxide and History – Hydrogen Peroxide and the Future

We’ve all heard about the automotive industry’s efforts to replace the internal combustion engine with a more environmentally friendly alternative. The most promising approach involves a new kind of battery – the ‘fuel cell’. Chrysler and Volkswagen are already using fuel cell technology in some of their vehicles; powered by a conventional electric motor which is quieter and simpler than the internal combustion engine, they deliver similar acceleration – and no noxious exhaust emissions.

The fuel in question is a mixture of hydrogen and air. Together, they generate a controlled chemical reaction in the fuel cell, producing electrical energy, and water as a by-product. There are two stages to the chemical reaction: at the end of the first stage, hydrogen peroxide is produced; in the second stage, the H2O2 is converted to H2O – ie water.

In road vehicles, engineers try to maximise the energy output by avoiding the formation of H2O2. It doesn’t take a huge leap of imagination to recognise that it might be possible to tweak the chemical reaction to produce H2O2 instead of H2O – and to maximise the production of H2O2 rather than electrical energy. A US research group has already sought patent protection for a fuel cell designed to generate H2O2 in a two-stage process – but it has not yet worked in practice.

Also, a British inventor has released the world’s first commercially available James Bond style rocket pack. The hydrogen-peroxide powered packs, dubbed “Rocket Belts”, can propel the wearer to speeds of up to 60 mph with their 800 horse power rockets.

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Introduction – Discovery – How is it Made?

Uses 1  – Uses 2 – Uses 3 

Hydrogen Peroxide and History – Hydrogen Peroxide and the Future

Hydrogen peroxide is manufactured today almost exclusively by the autoxidation of 2-ethyl-9,10-dihydroxyanthracene (C₁₆H₁₄O₂) to 2-ethylanthraquinone (C₁₆H₁₂O₂) and hydrogen peroxide using oxygen from the air.

In this reaction, the hydroxy groups on the middle ring of anthracene are deprotonated and are turned ketones, while two double bonds are lost from the middle ring and are replaced as C=O double bonds in the ketone groups. The derivative is then extracted out and reduced back to the dihydroxy compound using hydrogen gas in the presence of a metal catalyst. The overall equation for the process is deceptively simple:

H₂ + O₂ → H₂O₂

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Introduction – Discovery – How is it Made?

Uses 1 – Uses 2 – Uses 3

Hydrogen Peroxide and History – Hydrogen Peroxide and the Future

Hydrogen peroxide is familiar to most people as an over-the-counter preparation that is easily available at supermarkets as well as pharmacies, and is used as an antiseptic for cleansing minor cuts and scrapes. It was first used as an intravenous infusion in 1920 by a British physician in India, T. H. Oliver, to treat a group of 25 Indian patients who were critically ill with pneumonia. Oliver’s patients had a mortality rate of 48%, compared to the standard mortality rate of 80% for the disease. However, During the Second World War some extermination camps experimentally killed people with hydrogen peroxide injections.

In the 1920s, an American physician named William Koch experimented with hydrogen peroxide as a treatment for cancer. He left the United States after a legal battle with the FDA. In the early 1960s, researchers at Baylor University studied the effects of hydrogen peroxide in removing plaque from the arteries as well as its usefulness in treating cancer

                                                                                                                                                                                   On August 12th 2000,  the Kursk (a nuclear attack submarine) was taking part in a naval exercise off the Kola peninsula, when there was an explosion on board, equivalent to about 100 kg of TNT. It seemed to have been caused by a leak of hydrogen peroxide fuel from a torpedo. This caused a fire, which detonated several other torpedoes, leading to a much bigger explosion 135 seconds later, reportedly with a force of around 7 tons of TNT (recorded by seismic stations 5000 km away, measuring 3.5 on the Richter scale). The submarine sank in 108 meters of water. The entire crew of 118 men were lost.

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Introduction – Discovery – How is it Made?

Uses 1 – Uses 2 – Uses 3

Hydrogen Peroxide and History – Hydrogen Peroxide and the Future

How does peroxide bleach hair?

It uses a very slightly alkaline hydrogen peroxide solution.Hydrogen peroxide oxidises the melanin pigment inside the hairs to a colourless substance; the alkali makes the hair more permeable to the H₂O₂ by softening the cuticle, so the peroxide can reach the melanin.Blonde hair became increasingly popular since this discovery, for example:

films: Platinum Blonde (1931), Gentlemen Prefer Blondes (1953), Legally Blonde (2001)

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Introduction – Discovery – How is it Made?

Uses 1 – Uses 2 – Uses 3

Hydrogen Peroxide and History – Hydrogen Peroxide and the Future

Rocket Fuel

The Messerschmitt 163 rocket aircraft (“Komet”) wasn’t a conventional jet aircraft, it was the only rocket aircraft to ever fly in operational service in WW2. It was fitted with a rocket motor that made it faster than any other fighter in the air, but the fuel made it very unsafe. The fuels were “T Stoff” (80% H₂O₂, 20% water) and “C Stoff”. It is said that any organic matter (including humans) could spontaneously combust in contact with the T Stoff. The fuel was loaded separately, with the aircraft and crew washed down carefully after the first fuelling, and again after the second one. A catalyst (Ca(MnO₄)₂ + K₂CrO₄) was mixed with some peroxide, generating a mixture of steam and oxygen that drove the pumps feeding the two fuels to the combustion chamber. The explosive reaction produced a mixture of hot gases, steam and nitrogen:

2 H₂O₂ (l) + N₂H₄ (l) –> 4 H₂O (g) + N₂ (g)

Unfortunately, if a Me163 crash landed and somehow did not explode (they usually did), fuel lines could fracture, and the pilot would be dissolved alive by the T Stoff.

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Introduction – Discovery – How is it Made?

Uses 1 – Uses 2 – Uses 3

Hydrogen Peroxide and History – Hydrogen Peroxide and the Future

Around 2 million tons of hydrogen peroxide are made each year. About half of that is used to bleach wood pulp or paper. It is seen as an environmentally friendly alternative to chlorine-based bleaches. In domestic uses, it is used as a mixture with NaOH to bleach wooden surfaces. It is also used to bleach textiles.

Medically, hydrogen peroxide is used to disinfect skin, as it can kill bacteria by using its oxidizing power. When it comes into contact with a cut, it fizzes as oxygen is released, probably due to the action of catalase in the blood. Dilute H₂O₂ solution (around 3%) is used as a mouthwash, and also for cleaning and disinfecting contact lenses.

It also bleaches teeth and is a key ingredient in making glow sticks!

Controversially, it has been suggested that use of hydrogen peroxide solution – for example in very low concentrations intravenously – can be used as a therapy for cancer (“oxygen therapy”). The American Cancer Society says that there is nothing to support this, and that it may well be harmful.

Fun Fact: Hydrogen peroxide, if spilled on clothing (or other flammable materials), will preferentially evaporate water until the concentration reaches sufficient strength, then clothing will spontaneously ignite.

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Introduction – Discovery – How is it Made?

Uses 1  – Uses 2 – Uses 3 

Hydrogen Peroxide and History – Hydrogen Peroxide and the Future

Hydrogen Peroxide was first dicovered by Louis- Jacques Thenard in 1818 by burning barium salts to create barium peroxides. When the Barium peroxides were put into water to dissolve, Thenard found that hydrogen peroxide was produced.

Hydrogen Peroxide is a is a strong oxidizing agent and a weak acid in water solution. The formula is similar to that of water, with an extra atom of oxygen attached, H2O2. It is completely soluble in water. Pure anhydrous hydrogen peroxide is a colorless to pale blue  syrupy liquid which decomposes violently into water and oxygen if heated above 80 C. it also decomposes in light and in the presence of metal ions or oxidizable organic materials.  One volume of hydrogen peroxide releases ten volumes of oxygen when it decomposes. The most valuable property of hydrogen peroxide is that it breaks down into water and oxygen and therefore does not form any persistent, toxic residual compounds.

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Introduction – Discovery – How is it Made?

Uses 1 – Uses 2 – Uses 3

Hydrogen Peroxide and History – Hydrogen Peroxide and the Future

HYDROGEN PEROXIDE

H2O2

Household Disinfectant, Rocket Fuel, and Bleached Blondes in One Bottle…

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