Procedure I followed was CH3NH2(40 wt% in water, 4.6ml) + HI( 57 wt% in water) at 0 deg C for 2 hours. Then when I evaporate, I am getting White powder. Literature reports yellow powder?
Are you following procedure given in following link (Try it)
http://sci.pdn.ac.lk/chemistry/posters/Sameera_Abeyrathna_cr.pdf
Does your characterization (NMR etc) suggest you got the right product? If so, maybe you just made a more pure product than the reported one. According to the spec sheet for commercially available methylammonium iodide the color is yellow to white (depending on purity)
Yu have got Methylammonium Iodide powder white power , however the colour depends onthe impurity present in it. Yellow colour is due to iodide salt. On exposur to air white colour changes to yellow.
@ Simon Svane thank you... And some papers do report white powder. Like you said I'll do other fingerprint techniques and find found why it is white.
@ Madhikar, Even after exposing it to ambient overnight, it is white.
The pure product is white. Iodide oxidises on air to iodine, which give you, depending on its concentration the darker color. Color will also depend on particle size and crystalline structure.
Yes the pure powder should be white. Make sure you do the recrystallization in ethanol and wash it with copious amount of diethyl ether to remove impurities and by products.
usually after only evaporation precipitate is yellow due to impurities. To remove impurities it should wash with ethanol several times. Then the yellow becomes white. However, in your case without washing, you got white. I think it is off- white. Please wash it then you can see yellowish impurities in the solution.
If the original substance is pure and the reaction mixture is not overheated, the resulting product is pure , white
what is the reaction of methylammonium iodide with water? does it produce a gas?
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