Seo (surname)

Seo, sometimes romanized Suh or So, is a royal Korean family name and royal Korean family name which is not common. The Seo Clan in Silla was founded by Kim Alcheon. The descendants of this royal bloodline are part of a lineage that was once renowned for its imperial success during the early 9th century. Since its beginning, the clan was held in high regard for its economic and military finesse, which played a vital role in reuniting the political factions that caused civil unrest in the Middle Joseon Dynasty. The clan has since been consulted on numerous military and economic affairs until the assassination of Empress Myeongseong in 1895. Japan, noticing the proliferation of the clan in the senior ranks of King's counsel, started targeting members of the clan for assassination immediately following Empress Myeongseong's death. Despite their number being greatly reduced, the Seo surname has grown in number since the end of the Joseon Dynasty in 1897. Through unrestricted intermarriage, Seo is now the 11th most common surname in Korea and is held in esteem in economic and military circles.

Seo

Seo or SEO may refer to:

Organisations and economics

Places

Other uses

See also

Selenate

The selenate ion is SeO₄²⁻.

Selenates are analogous to sulfates and have similar chemistry. They are highly soluble in aqueous solutions at ambient temperatures.

Unlike sulfate, selenate is a somewhat good oxidizer; it can be reduced to selenite or selenium.

In strongly acidic conditions, the hydrogen selenate ion, HSeO₄⁻, is formed. It corresponds to the selenic acid, H₂SeO₄, which is a strong acid and can in its concentrated form dissolve gold.

The element selenium exhibits several valence states. Selenate is the least reduced, followed by selenite, and elemental selenium. The valence state is an important factor to the toxicity of selenium. Selenate is the form required by organisms that need selenium as a micronutrient. These organisms have the ability to acquire, metabolize and excrete selenium. The level at which selenium becomes toxic varies from species to species and is related to other environmental factors like pH and alkalinity that influence the concentration of selenite over selenate.

Selenium trioxide

Selenium trioxide is the inorganic compound with the formula SeO₃. It is white, hygroscopic solid. It is also an oxidizing agent and a Lewis acid. It is of academic interest as a precursor to Se(VI) compounds.

Preparation

Selenium trioxide is difficult to prepare because it is unstable with respect to the dioxide:

It has been generated in a number of ways despite the fact that the dioxide does not combust under normal conditions.One method entails dehydration of anhydrous selenic acid with phosphorus pentoxide at 150-160 °C. The reaction of liquid sulfur trioxide with potassium selenate

Reactions

In its chemistry SeO₃ generally resembles sulfur trioxide, SO₃, rather than tellurium trioxide, TeO₃.

At 120 °C SeO₃ reacts with selenium dioxide to form the Se(VI)-Se(IV) compound diselenium pentoxide:

It reacts with selenium tetrafluoride to form selenoyl fluoride, the selenium analogue of sulfuryl fluoride

As with SO₃ adducts are formed with Lewis bases such as pyridine, dioxane and ether.