Redox reaction [KMnO4 + Fe]

[neu4vhg]

Why is it orange before it gets colorless? :(

[hkchem]

@neu4vhg this is due to the mixture of Fe3+(orange-yellow) and MnO4-(purple)

[neu4vhg]

@hkchem Thank You! And thanks for making this video.:)

[cornerstorefuneral]

sodium bisulfite works much better/faster than iron. It just smells horrid.

[KIVPA]

Is the given equation 8H+ + MnO4 + 5Fe(II) --> 5Fe3+ + Mn2+ + 4H2O correct?

I`m trying to solve it, but i only get to this;

Oxidator = Mn8+ + 6e --> Mn2+

Reductor = 5Fe(II) --> 5Fe(III) + 5e

I`m missing 1 electron.....

[hkchem]

@KIVPA as KMnO4, K is a spectator ion, MnO4- carry a negative charge, which Mn oxidation state is +7 instead of +8 in your equation, which account for the missing electron

[KIVPA]

@hkchem Thanks!

[hkchem]

as u said, Fe metal is a reactant, which is converted to Fe2+, which is the final product

[0773494599]

according to the experiment it seems to be a reaction between Fe metal and KMnO4 but the final reaction include Fe2+ ions instead of Fe why?

[themert123456]

@hkchem

what are the two big things at the end?

[hkchem]

@themert123456

it is the excess iron wire i added at 0:26 and 1:16, which left after the experiment

[iliya1997]

@themert123456  gess

[syk619]

What is the conclusion of this experiment?

[hkchem]

@syk619 MnO4- will react with Fe metal in acidic medium, which is a redox reaction

[hkchem]

@syk619 MnO4- will react with Fe metal in acidic medium, which is a redox reaction, giving colorless Mn2+ and Fe3+

[TheMedKing]

intense man, man keep it up,

I have this question, can help me solve it: sodium iodide+ hydrogen peroxide-- what will be the product? its a redox reaction.

[hkchem]

@TheMedKing in the reaction u talk about: iodide ion become iodine, while hydrogen peroxide decompose to oxygen and water. that is the famous elephant toothpaste experiment.

[shidoink]

it was pretty at about 1:35. then it got kinda nasty looking.

[TheHappyShack]

naaiicceee



[EhtYlno]

manganate 7+ ions are oxidised to Manganate 2+ ions, which changes the color of the solution to COLORLESS

[hkchem]

= ]

[Zink575]

@EhtYlno how about reduced to Manganous 2+ ions.... Chemistry win

[techypyromaniac]

so what is it just speeding up the oxidation process and giving off rust?

[hkchem]

actually, it is not give out rust. since rust is Hydrated iron(III) oxide, where formula is Fe2O3.xH2O, which is insuloable. in that reaction, Metallic iron change to iron(III) oxide. it is true for u to say that iron reduced to iron(III) ion, but not rust actually =]

[pokestep]

If i would use powder iron, it would be grey, right? Cause i have used it, and it is just making bubbles and it is all grey XD And we dont have in school nonpowder Fe :D Thx for answerNice video, gonna ude it on our Chemistry, for experiment Fe+Co+Ni :D

[hkchem]

as u said, "it is just making bubbles"........i think this is due to the reaction between the hydronium(H+) ion(it comes from the acid when your acidify the solution) and Fe powder. As you use iron powder(which have a larger surface area), so the bubbles that u observed should be hydrogen gas. thanks for watching :D

[pokestep]

So it will be grey, yes? Cos it turned grrey and we let it for a weekend and so on... We are waiting what it will do XD Anyway thanks :D

[hkchem]

Probabily, it is maganese dioxide(MnO2), cuz the acid is used up and the reaction will undergo in alkaline medium

[TheRolemodel1337]

so mno2 is also reduces by iron?

because it's not getting brown :p

[hkchem]

ya......MnO2 --> Mn2+

[fzul12]

tx a lot,im malaysian student

[arlun1222]

thx for the video,

btw what is the solid at the end of the experiment?

[hkchem]

the solid is the Iron wire as the wire is in excess.

the iron wire was put in 27 second in the vid

[arlun1222]

thanks for answering=]

[gokilaja2008]

btw, thanks for the vid

I'd show this to my students

[hkchem]

Thanks for your appreciation

[gokilaja2008]

i think the overall reaction is not Fe2+ in the beginning, because u put the Fe wire in it. it should be Fe(s). then with the MnO4- it is oxidized to Fe2+ or Fe3+. all the metal is reductor.

[hkchem]

ya .......... as MnO4- is strong oxidizing agent, the Fe will directly become Fe3+

[karthikok]

instead of h2so4 can hcl be used

[hkchem]

No.......because the permagnet ion will oxidize the chloride ion to form chlorine gas..............and this will affect the result

[hkchem]

umum...actually, it is quite not possible to turn Fe3+(from iron(III) hydroxide) back to Fe2+(iron(II) sulphate), so i think your blue-green solution is come from some inpurities.............copper(­II) ion is most likely wt you discribe. may be i should try to put for a day next time i redo this exp.

[kittymomo123123]

also

Fe(OH)3 is insoluble,isn't it?

So how it become Fe3+ in the water?

[hkchem]

actually.....i mean....Fe(OH)3 is insoluable.....so brown(the ions are very concentrate) and this is wt u know from book..........

[hkchem]

Now, in the experiment, the Fe3+ ion is soluable.....

[hkchem]

so the Fe3+ ion saprate very far.......and this is why it looks yellow........

and also ......the CE accept std write yellow or brown for Fe3+ in the exam....

[kittymomo123123]

great

i learn a lot from this expt.

do you have msn?

i have a lot of chem problem

maybe that is my misconception

[hkchem]

check the mail i sd to u

[kittymomo123123]

fe3+ is brown

I learn it from my book

[hkchem]

HaHa..........Hong Kong guys..........dont just copy stuff directly from your book........be flexable...........

wt i want to say is......

Fe(OH)3 is brown........because the density of Fe3+ is very high(Fe3+ ion packed closely).........so it looks brown.....

when it is a soluable ion in water.......the Fe3+ ion spread out...........so it become pale yellow.....

ya.......Hong Kong education system is bad.......i hate it really much........u may learn alot from experiment =)

[hkchem]

Brown is the Fe2+(green) and Mno4-(purple).........

colorless is the Fe3+(pale yellow) and Mn2+(pale pink).

[kittymomo123123]

y it will from brown to colourless at the end?