jarmenkill

tanx

thanks a lot

really helpful

thanks

You use one solvent to dissolve all the crude product and then add the second, which your product is insoluble in, to force the recrystalitsation. An example of this is sodium chloride dissolves in water, then add a few drops of acetone and the sodium chloride crystalises out

so what is the effect of the second solvent? i mean why it decrease the solubility of the crude ? could you please give me a molecular approach of why this happens?

might one of you guys please tell me what is the theoretical background of the mixed solvents recrystallization ?

how could i get some luminol? or any other material that does its work?

hi

i don't know that temperature exactly BUT you may use burning magnesium bar to ignite it.

plastic sulphur? whats this?

(I know its a plastic, or is it)

if you pour melted sulfur in cool water you will see that:D

all double bonds have a pi and a sigma bonds.

all triple bonds have 2 pi(s) and one sigma bonds.

why?

hybridization orbitals will make a sigma bond.(two orbitals will get face to face)

excess P orbital(s) may make 1(2) pi bonds.

take a look at orbitals spatial shapes.

a solution with only CH3CH2COOH will not make a buffer ! you should anoter thing like NaCH3CH2COO

for your question , you must have the Ka of CH3CH2COOH .

methane has 4 electrons groups so it has a 109 28' angel between CH bonds.

for 3 groups of electrons we will have 120 degree(s) angel.(and so 3 bonds are in a plate) for example see BF3

for more info see VSEPR theory