STAR CHEMISTRY

this article tells about how we are able to see an objects in our eyes by chemistry aspect .the process of vision is mainly caused by photo chemical reaction . naturally we have retinal ( vitamin A) in our eyes in the cis form , one of the protein also have in our body called opsin  that is helpful in  conversion of cis retinal to trans retinal . when hitting a light radiation in complex of 11-cis retinal and opsin ,this leads to conversion of cis retinal to trans retinal .  trans retinal is helpful to sending images to brain by photo chemical signal. that's why we are able to see. the systematic reaction shows in above picture   

The reduction of aromatic compounds to 1.4-cyclohexadiene compounds in   presence of alkali metal liquid ammonia and an alcohol is called Birch reduction. A variety of aromatic compounds containing electron donating or electron withdrawing groups could be readily converted to the corresponding 1,4 cyclohexadiene derivatives. The regioselectivity towards the products in Birch reduction of substituted  aromatic compound depends on the nature of the substituent. For example, the  electron donating substituent such as alkyl or alkoxy group remains on the  unreduced carbon where as the electron withdrawing groups such as carboxylic  acid or primary amide remains on reduced carbon almost exclusively. The aldehydes and esters groups are in the electron donation side because  these are reduced to the corresponding alcohols in Birch condition before the  reduction of aromatic ring . The addition of one or two equivalent of  water ...

nitric acid reacts with our hands, which contain proteins of aromatic amino acids.it forms the yellow stains in our hand , because of nitration takes place in the aromatic amino acid rings to form the yellow color  nitrated amino acid. this reaction is carried by xanthoproteic test.

       Prussian blue used industries :                                              pharmaceutical industries                                              dye chemical industries                                                                                                    ink industries               annually 12,000 tonnes is required only for ink industry  uses of Prussian blue: the Prussian blue is widely used in oil,water color...

upon mixing cement powder with water ,part of  the tricalcium aluminate and gypsum dissolved and react together forming ettringite . the ettringite crystal on the surface of the cement particals are so fine that they cannot bridge the gap between structure .this is the basis of the delay in solidification upon adding gypsum to cement . if we mix cement with water without adding gypsum the tricalcium aluminate immediately reacts with water to form calcium aluminate hydrate . which fills the gap between the cement particals with large crystals and leads to very rapid solidification of the cement slurry