Oxidising Strengths (1 Viewer)

[toknblackguy]

what's a practical that demonstrates the oxidising strengths of kmno4?

thanks

 

[mon_mon]

compare it to H2O2. Hydrogen peroxide is stronger, but they both will oxodise anything...except H2O2 of course. i cant remember what happens when you mix them, but i theory KMnO4 should be oxidised, although thats imsoible. maybe it justs explodes.

 

[toknblackguy]

hahahaha
for a person of class of 04
you know a heck of a lot of the hsc syllabus!

but i think i need something more than that...like a breif procedure, and perhaps some theory behind it
thanks

 

[Frigid]

try crushing KMNO4 in a mortar/pestle and add glycerol and see what happens ...

actually don't.. hahahaha...

this was my first science demo in year 7, and the fireworks were good...

edit: mr. mon_mon, i have a feeling ur an accelerator of chem, am i correct?

 

[toknblackguy]

hahaha
frigid..you do shipwrecks right?
this questino is aimed at chem fo art..but is there a chance you know asomething?

 

[Frigid]

hate to break it to ya token but no... perhaps phenol might tho.

 

[mon_mon]

lol. our teacher did that. you could mix it with a chunk of gold for the most kickarse battery.

 

[phenol]

sorry, permanganate FULLY owns H2O2 at oxidising ability

good demonstration?

hot acidified permanganate can cleave a double bond (in carbon chain) like *clicks finger* that

 

[toknblackguy]

hahaha
cleave?
wtf....better explanation phenol plz

 

[phenol]

cleave in organic chemistry means break (cleaving a bond means breaking a bond)

hot acidified permanganate is one smooth oxidising agent. I got cold acidified permanganate on my hand (for a couple of seconds) during summer school and it STAINED (oxidised my skin)!!

many organic chemists use hot acidified permanganates to rip (this is the best verb to use here) the electrons from double bonds and break the chain into two fragments. (ozone can also do this)

a better (cheaper and safer) experiment showing the oxidation strength might be rapid discolouration of acidified permanganate by an alcohol (not tertiary) (i.e. shove ethanol into kmno4 - goes clear)

or discolouration of kmno4 by cyclohexene (cyclohexene into kmno4 dissolved in acetone - goes clear)

else u gotta have faith in me, KMnO4 is much smoother than hydrogen peroxide

 

[spice girl]

or dunk some permang in saturated NaCl...

and don't kill yourself when taking a sniff

phenol, have u had conc HNO3 on your hands yet? it stains a different colour...

 

[mon_mon]

Nah, H2O2 is a far better oxidiser, it probably wasn't for you becasue they dilute it. its Eo value is about +1.0 more. thats a shirtload more.

 

[phenol]

spice - do you remember the nitration of phenacetine prac @ summer camp? i decided to not use the gloves when pouring 10M nitric into a measuring cylinder - regretted that for two or three weeks

 

[phenol]

mon mon, the potentials dont say ANYTHING about reaction rate
further, the oxidation state of manganese in KMnO4 speaks for itself i think

i am sure u'll realise when you do the experiments, hot acidified permang is a monster (goes at the click of your finger)

 

[mon_mon]

fcuk! thats pretty harsh. 10M you say? jesus! Our teacher got us to apply Silver Nitrate all over our hands and add a bit of NaCl just to top it off. he then laughed at our purple hands for the next 2 weeks.

 

[phenol]

u cant do nitration of benzene rings with pussy 1 molar nitric can you

 

[Frigid]

Originally posted by mon_mon
he then laughed at our purple hands for the next 2 weeks.

ass....

no wonder han got scared when i threatened him with 20M H2SO4 while making the ester... hehehe

 

[phenol]

dude u cant get 20M H2SO4
18M is like max

nitric owns - goes full brown then skin peels off after several weeks

 

[mon_mon]

lol. you got told by the master phenol. and teh hand thing was on our first day, we had no idea.

 

[Frigid]

Originally posted by phenol
dude u cant get 20M H2SO4
18M is like max

hahaha... luithle's a liar then... well han was scared...

nitric, does that hurt?