Sciencemadness Discussion Board

Need your opinion, advise and suggestions, please...please!!

pokeh - 12-12-2007 at 18:01

Dear All,

I tried to conduct one experiment this time but do not understand about some reaction. My experiment detail as below;

1. Mixing all chemicals together in crucible cup

[LiOH (s) + H2O2(l) + LiNO3 (s) + SnCL2(s)].

2. Dry this mixtures at 120C in Vacuum Oven for one night.

[Info]
Melting point for LiNO3 and SnCL2 are above 240C.
Vacuum oven is a equipment that suck the air inside the oven and flow it into outside the oven.

My explaination refer to what i understood as below;
At 120C, only LiOH and H2O2 will involved in the reaction and the equation reaction will be as below;

2LiOH + H2O2 ----> Li2O + H2O + H2 + O2.

If this reaction is correct, H2O, H2 and O2 will released onto air and remaining Li2O together with LiNO3 and SnCL2. My experiment not finish here, but i want to know about the reaction at this stage first.

So, i would like to know from expertises outside or inside there and here to give some opinion, advice and suggestion about my experiment above.

[Edited on 13-12-2007 by pokeh]

12AX7 - 12-12-2007 at 20:18

That's a strange mixture to put together...

How pure is the H2O2?

I would suppose it would oxidize the SnCl2, in spite of its not being dissolved. Certainly when hot enough, the nitrate would oxidize it to lithium stannate.

Tim

not_important - 12-12-2007 at 20:30

Quote:
[LiOH (s) + H2O2(l) + LiNO3 (s) + SnCL2(s)


Immediately makes LiCl and Sn(OH)2

Sn(OH)2 is easily oxidise, likely the H2O2 will do so

Quote:
2LiOH + H2O2 ----> Li2O + H2O + H2 + O2.


rather unlikely. Heating LiOH hot enough results in it going to Li2O and water, true, but that's around 700 C or more. The H2O2 will have boiled off long before.

H2O2 will fall apart into H2O and O2 at a much lower temperature, not going to get an H2 + O2 mix.

pokeh - 12-12-2007 at 20:44

Ok Thanks for your inputs,

The purity of H2O2 is 35%, LiOH 99%, SnCL2 90% and did not mentioned for LiNO3.

We got Sn(OH)2 and LiCL instantly at 120C?
What i understood regarding to the melting point of substance, this MP temperature will brake the force bonding between 2 molecular. So this time the full reaction can/will be happen. (correct me if i am wrong). But how can we get Sn(OH)2 and LiCL immidietly.

So these mixtures product at this stage are Sn(OH)2 and LiCL and also LiNO3. This is what i understood from the answer of "not important", is it correct?.

Lets me give details about my experiment,
after number 2 process, number 3 take part. This mixtures was heated at 300 C for 2 hours, then cooling at room temp.







[Edited on 13-12-2007 by pokeh]

not_important - 12-12-2007 at 21:28

The H2O2 is 65% water, LiOH and SnCl2 are fairly soluble; they're even reasonably soluble in 100% H2O2. Try mixing in a test tube, then filtering, and see what you got.

pokeh - 13-12-2007 at 14:01

ok..i understand what are you saying, how about LiNO3, it 100% soluble in water also also must take reaction too,

Let me guess from what i am understood,

SnCL2 + LiOH + LiNO3 + H2O2 --> Sn(OH)2 + 2LiCL + HNO2 + O2

Is it can be like above?

can i get your answer for this part?



[Edited on 14-12-2007 by pokeh]

12AX7 - 13-12-2007 at 18:03

Why would you make a reduced acid when there is oxidizer and very strong base around? I mean really, what gives? You didn't even balance the lithium, and probably other things.

Tim

not_important - 13-12-2007 at 18:13

Quote:
SnCL2 + LiOH + LiNO3 + H2O2 --> Sn(OH)2 + 2LiCL + HNO2 + O2


no


SnCl2 + 2LiOH + LiNO3 + H2O2 --> Sn(OH)2 + 2LiCl + LiNO3 + H2O2

As you heat it the H2O2 might oxidise the Sn(OH)2 to the hydrate Sn(IV) oxide.

As you continue to heat the LiNO3 will eventually break down into Li2O and NOx and O2, if the is Sn(II) remaining it will be oxidise meaning possibly no O2 given off unless there's an excess of LiNO3. Oxidation of Sn(II) will happen before the mix is completely dry. Anhydrous LiNO3 melts at about 260, and is used as a component of moltan salt baths in the 250 to 350 C range.

JohnWW - 13-12-2007 at 23:05

I am sure that the aqueous H2O2 would instantly hydrolyse the SnCl2 and oxidize it to hydrous SnO2.

Dr. Beaker - 14-12-2007 at 14:49

H2O2 is a bit more acidic them H2O so under exreem alkline conditions LiHO2 is likely to be formed, being a salt it can stay in the mixture even at vacuum or elevated temp. unlike H2O2. I also speculate it should be more thermally stable then H2O2.
it can also do metathesis with the tin chloride, but it's reasonable the tin II hydroperoxide would be unstable in regard to self redox and decompose to SnO2 and water.

pokeh - 14-12-2007 at 23:18

Thanks geng...i got your answers.

I realized that my equation is uncorrect after i make review at home, by the way thanks to you all, i am not regret to be a member here.

Another question.

Before i procceed to do this experiment i need to fill up the risk accessment for this experiment due to some explosive happen before this. I do not know what elements that involve in that explosion, may be NOx mixed O2 or sugar (for your information i have put some sugar and heated in tube furnace under Argon atmosphere).

My question is, There are any elements above which can react with argon gas and make the explosion?

Thanks.

not_important - 14-12-2007 at 23:33

Quote:
Originally posted by pokeh
...
My question is, There are any elements above which can react with argon gas and make the explosion?


Argon has one known compound http://physicsworld.com/cws/article/news/2793
which only exists at temperatures around the boiling point of hydrogen or lower, and require zapping by UV to make.

You've been suggesting reactions that seem surprising coming from someone with access to what you say you have.

JohnWW - 15-12-2007 at 08:51

In addition to HArF and possibly ArF2 formed at cryogenic temperatures by UV irradiation of the frozen HF clathrate of Ar, it just might be possible to make ArF2 under extreme conditions of heat and pressure like KrF2, which itself after isolation is stable only below -100ÂșC and slowly decomposes at room temperature. Like the cation KrF+ as in [KrF][SbF6], it is likely that the ArF+ cation, isoelectronic with ClF, would be the only argon compound likely to be stable at room temperature. It has been supposed that the tetroxide ArO4, isolectronic with ClO4-, might be stable, and may be a possibility resulting from the beta-decay of Cl-38 as perchlorate to Ar-38.