Arsenic pentoxide is a white, odourless solid. It dissolves easily in water to make arsenic acid. It is highly toxic, as are almost all arsenic compounds. It is a powerful oxidizing agent. It reacts with hydrochloric acid to make chlorine. AsO breaks down to arsenic trioxide and oxygen when heated to about 300°C.
It reacts with bases to make arsenates. The energy for the reaction is taken from the heating.
Arsenic pentoxide cannot be produced by burning arsen. That only results in AsO. To produce arsenic pentoxid, arsenic acid will be dehydrated. This is done with phosphorus(V) oxide.
The arsenic pentoxide drops out as white powder.
Arsenic pentoxide is used to make pesticides and insecticides. It is also used in glass industry.
Arsenate
Arsenate is an ion. Its chemical formula is AsO. It has arsenic in its +5 oxidation state.
Arsenates are salts of arsenic acid. They are oxidizing agents. Sometimes, not all of the protons are taken away from the arsenic acid and then hydrogen arsenate salts are formed. Their chemical formulas are HAsO or HAsO.
Arsenate can replace phosphate in the cells but it does not work like a phosphate does. The cell dies, and that is why arsenates are toxic. Some bacteria can use arsenate instead of phosphate, though. They are called arsenic bacteria.
Arsenates occur naturally in a variety of minerals. Those minerals may contain hydrated or anhydrous arsenates. Unlike phosphates, arsenates are not lost from a mineral during weathering. Examples of arsenate-containing minerals include adamite, alarsite, annabergite, erythrite and legrandite.
Arsenic acid
Arsenic acid is a chemical compound. It is also an acid. Its chemical formula is HAsO. It has hydrogen and arsenate ions in it.
Arsenic acid is a colorless solid. It absorbs water from the air. It is a strong oxidizing agent. It is similar to phosphoric acid. It can be deprotonated three times, making various arsenates. Arsenic acid reacts with iodide to make iodine.
It is made by reacting moist arsenic with ozone or by reacting arsenic trioxide with concentrated nitric acid. It can also be made by dissolving arsenic pentoxide in water.
Arsenic acid is used in the making of some dyes and organic arsenic compounds. It is also used as a preservative for wood and a biocide (something that kills all living things).
Breccia
Breccia is a type of rock formed of broken fragments of minerals or rock cemented together by a fine-grained matrix. The matrix may be similar to or different from the composition of the fragments.
Rocks formed by sticking together pieces of previous rocks (clasts) are called clastic rocks. There are two types of clastic rock: conglomerates and breccias. What divides these two categories is the amount of rounding. The particles that make up conglomerates are well rounded, whereas in breccias they are angular.
A breccia may have a variety of different origins, as indicated by the named types including sedimentary breccia, tectonic breccia, igneous breccia, impact breccia and hydrothermal breccia.
The basic sequence is as follows. Sediment is laid down in the sea, and is gradually transformed into sedimentary rock. After a long period of time something violent happens to the rock, breaking it up into many jagged pieces. Later the pieces are cemented together by another deposition, forming a new sedimentary rock. This is a breccia. On examination, the rock is seen to include fragments of the original rock.
Brecciated marble can have a marvellous appearance. The Pantheon in Rome is full of the most wonderful marble, many of which are breccias. It includes two gigantic columns of pavonazzetto, a breccia coming from Phrygia (in modern Turkey). Pavonazzetto obtains its name from its extremely colourful appearance, which is reminiscent of a peacock's feathers ("pavone" is "peacock" in Italian).
Lead arsenate
Lead arsenate is a chemical compound. Its chemical formula is PbHAsO. It has lead, hydrogen, and arsenate (HAsO) ions in it. The lead is in its +2 oxidation state.
Lead arsenate is a white solid. It is highly toxic because of the lead and the arsenic in it. It does not dissolve in water.
It was made by reacting lead nitrate with arsenic acid.
It was the most used insecticide that had arsenic in it. It was used against the potato beetle and the gypsy moth. It replaced the even more toxic Paris Green. It was later used to kill certain moths, mosquitoes, and pests of cranberries. It was found that it stayed inside fruits even after washing off, so it was replaced with DDT. It was completely banned in 1988.
Potassium arsenate
Potassium arsenate is a chemical compound. Its chemical formula can be KAsO, KHAsO, or KHAsO. It has potassium and arsenate ions in it.
Potassium arsenate is a white solid. It dissolves easily in water. It is an oxidizing agent. It is carcinogenic and highly toxic.
Potassium arsenate is made by reacting amounts of potassium hydroxide with arsenic acid. The amount of potassium hydroxide can be changed to make the different chemical formulas. Potassium arsenate was once used for medicine but is too toxic to be used now.
Clastic rock
Clastic rocks are composed of fragments, or clasts, of pre-existing rock.
Although, in principle, almost any rock made of eroded former rock is clastic (such as sandstone or mudstone), in practice the term is used for clasts of at least gravel size upwards. That means clasts are at least visible to the naked eye, and may be huge.
There are two types of clastic rock, by shape. conglomerates have rounded clasts, and breccias have jagged clasts.
In a clastic rock, the clasts are often of a different make-up from the ground rock or matrix.
Spandau Prison
Spandau Prison was a prison situated in the borough of Spandau in the British Sector of West Berlin.
The prison was built in 1876 and knocked down in 1987 after the death of its last prisoner, Rudolf Hess. This was to stop it from becoming a neo-Nazi shrine.
The prison was built in 1876. At first it was only used for soldiers but after 1919 it was also used for civilian inmates. It held up to 600 inmates at that time.
In the aftermath of the Reichstag Fire of 1933, opponents of Hitler and journalists such as Egon Kisch and Carl von Ossietzky were held there in so-called protective custody. Spandau Prison became a sort of predecessor of the Nazi concentration camps. It was supposed to be controlled by the Prussian Ministry of Justice but the Gestapo tortured and abused its inmates, as Egon Erwin Kisch recalls in his memories of Spandau Prison. By the end of 1933 the first Nazi concentration camps had been built (at Dachau, Osthofen, Oranienburg, Sonnenburg, Lichtenburg and the marshland camps around Esterwegen). All remaining prisoners in "protective custody" in state prisons were transferred to these concentration camps.
After World War II it was operated by the Four-Power Authorities to house the Nazi war criminals sentenced to imprisonment at the Nuremberg Trials.
Only seven prisoners were finally imprisoned there. Arriving from Nuremberg on 18 July 1947, they were:
Of the seven, only four served all of their sentence; the remaining three, Neurath, Raeder, and Funk, were released early due to ill health. Between 1966 and 1987, Rudolf Hess was the only inmate in Spandau Prison. His only companion was the warden, Eugene K. Bird, who became a close friend. Bird wrote a book about Hess's imprisonment entitled "The Loneliest Man in the World".
Spandau was one of only two Four-Power organizations to continue to operate after the breakdown of the Allied Control Council; the other being the Berlin Air Safety Center. The four occupying powers of Berlin would alternate control of the prison on a monthly basis, each having the responsibility for a total of three months out of the year.