jarmenkill

tanx

thanks a lot really helpful

thanks 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.

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