ứng dụng của các oxit thuộc nhóm VIIB
 

- Cho mình hỏi ứng dụng của các oxit MnO, MnO2, Mn2O3, Mn2O7, TeO2, Te2O7, ReO2, ReO3, Re2O7? thanks!

Hơ, mấy cái này thì 1 là bạn tìm trong Hóa Vô Cơ của Hoàng Nhâm, hoặc là lên net tìm, mình nghĩ cũng chẳng khó khăn gì cả
Ví dụ
[CODE]
Ancient [URL="http://en.wikipedia.org/wiki/Cave_painting"]cave painters[/URL] and later the ancient Egyptians used MnO<SUB>2</SUB> as a black or brown pigment. One of its first uses was in glass making. Egyptian and Roman glasswares have been shown by analyses to contain over 2 per cent of manganous oxide. Pliny mentions the use of manganese oxide under the name of "magnes" among the Romans for decolorizing glass. He considered it a variety of lodestone or magnetic iron ore.<SUP class=reference id=cite_ref-3>[URL="http://en.wikipedia.org/wiki/Manganese_dioxide#cite_note-3"][4][/URL]</SUP> Eighteenth-century British chemists referred to MnO<SUB>2</SUB> simply as [I]manganese.[/I]<SUP class="noprint Template-Fact" title="This claim needs references to reliable sources since March 2009" style="WHITE-SPACE: nowrap">[[I][URL="http://en.wikipedia.org/wiki/Wikipedia:Citation_needed"]citation needed[/URL][/I]]</SUP>
In modern times, the predominant application of MnO<SUB>2</SUB> is as a component of dry cell batteries. Approximately 500M kg are consumed for this application annually. Two distinct synthetic forms of the dioxide are used for batteries, chemical manganese dioxide (CMD) and electrolytic manganese dioxide (EMD).<SUP class=reference id=cite_ref-Ullmann_4-0>[URL="http://en.wikipedia.org/wiki/Manganese_dioxide#cite_note-Ullmann-4"][5][/URL]</SUP>

[B] [/B]

A specialized use of manganese dioxide is as an oxidant in [URL="http://en.wikipedia.org/wiki/Organic_synthesis"]organic synthesis[/URL].<SUP class=reference id=cite_ref-5>[URL="http://en.wikipedia.org/wiki/Manganese_dioxide#cite_note-5"][6][/URL]</SUP> The effectiveness of the reagent depends on the method of preparation, a problem that is typical for other heterogeneous reagents where surface area, among other variables, is a significant factor.<SUP class=reference id=cite_ref-6>[URL="http://en.wikipedia.org/wiki/Manganese_dioxide#cite_note-6"][7][/URL]</SUP> The mineral pyrolusite makes a poor reagent. Usually, however, the reagent is generated by treatment of an aqueous solution KMnO<SUB>4</SUB> with a Mn(II) salt, typically the sulfate. MnO<SUB>2</SUB> oxidizes allylic alcohols to the corresponding aldehydes:
<DL><DD><DL><DD>cis-RCH=CHCH<SUB>2</SUB>OH + MnO<SUB>2</SUB> → cis-RCH=CHCHO + “MnO” + H<SUB>2</SUB>O </DD></DL></DD></DL>The configuration of the double bond is conserved in the reaction. The corresponding acetylenic alcohols are also suitable substrates, although the resulting propargylic aldehydes can be quite reactive. Benzylic and even unactivated alcohols are also good substrates. 1,2-Diols are cleaved by MnO<SUB>2</SUB> to dialdehydes or diketones. Otherwise, the applications of MnO<SUB>2</SUB> are numerous, being applicable to many kinds of reactions including amine oxidation, aromatization, oxidative coupling, and thiol oxidation[/CODE]

Nguồn
[CODE]http://en.wikipedia.org/wiki/Manganese_dioxide[/CODE]