[Brunusmcchunky]

Ive been asked to find out what happens when Helium is added to some dry ice. Im under the impression that it removes the CO2 but i dont know how ? , any help would be really appreciated  

[ARGOS++]

Dear Brunusmcchunky;

How is the group called containing Helium, Neon, Argon, Krypton, etc..
And where is its group name coming from?
(Maybe you have to search for.)

Why should it remove, and remove what?

Good Luck!
                    ARGOS⁺⁺

[Brunusmcchunky]

Ive been given a task in which frozen Carbon Dioxide is trapped in a length of pipe blocking it from being used. The pipe is at -160c and the blockage can only be reached by a chemical, its been hinted to me that Helium is suitable for the job but i wanted to know why and how, internet research and textbook research have failed me so far. if anything else needs clarification please let me know.

[ARGOS++]

Dear Brunusmcchunky;

But this question has not very much in common with the initial one and its headline.
So my question is:  What would you guess now with the new knowledge?

Good Luck!
                    ARGOS⁺⁺

[Brunusmcchunky]

Dear Brunusmcchunky;

But this question has not very much in common with the initial one and its headline.
So my question is:  What would you guess now with the new knowledge?

Good Luck!
                    ARGOS⁺⁺

Its does have a lot in common, i wanted to know whether Helium will react with Co2 , your cryptic answers do little to help , i would rather appreciate you telling me whether you could or couldnt answer my question rather than act superiorist because of my phrasing.

[ARGOS++]

Dear Brunusmcchunky;

It seems you don’t know about these Forums. 
We not simply answer only questions, but we guide you (too) in the right direction to find a solution.
(The name tells you something about the "reactions"!)

Maybe you please should also read:     "Forum Rules” (4.)

Good Luck!
                    ARGOS⁺⁺

[Brunusmcchunky]

Dear Brunusmcchunky;

It seems you don’t know about these Forums. 
We not simply answer only questions, but we guide you (too) in the right direction to find a solution.
(The name tells you something about the "reactions"!)

Maybe you please should also read:     "Forum Rules” (4.)

Good Luck!


                    ARGOS⁺⁺

Lol, okay . Sorry i didnt realise you were trying to hint to the answer. Thanks for the help i'll try to figure the rest out myself. Thanks again

[ARGOS++]

Dear Brunusmcchunky;

You may try to do the next steps, but keep in mind: 

We are still ready for future discussions and help.

Good Luck!
                    ARGOS⁺⁺

[Brunusmcchunky]

Am i  heading in the rigth direction because from what ive read because its a noble gas , and it has a full outer shell the gas is extremely inate. so it wouldnt react with the co2, however if this is true then what ive been told is right is actually wrong ?

[ARGOS++]

Dear Brunusmcchunky;

That’s absolutely correct!,  It is of very high inertness.

And there is nearly “nothing”, that will give a reaction at such low temperature.
My conclusion is that some physical property of something will act if it is possible.
So there is not much left like liquid N₂, or He, or H₂, or so.

Good Luck!
                    ARGOS⁺⁺

[enahs]

Well, technically it would work somewhat. But then again, so would air.

If you constantly move a warmer gas over a colder object, the object will warm up (application of the 0th, 1st and 2nd law of thermodynamics).

So if a pipe is frozen and you can blow helium on it, especially if it is warmer, then yes it would warm it up faster then if there was no air flowing over it.

The question becomes, would air be more efficient or would helium, then, given those conditions (but you are correct, there is no chemical reaction though).

Helium has a specific heat of almost 5 times that of air by mass, but my molar volume it is 2/3rds that of air.
So depending on how you measure it, it will be 5 times more efficient, or 2/3rds less efficient. Funny, but true.

[ARGOS++]

Dear enhas;

I don’t believe that’s a real solution, then it would be much easier to warm the pipe to –78°C and let the CO₂ sublimate and clean the pipe with much less N₂ gas. That would be more effective.

Maybe with He you can do the same at -100°C or less, even when the pipe is partially closed, because its high diffusion coefficients, according to the phase diagram of CO₂ (maybe with less pressure too):

http://scifun.chem.wisc.edu/chemweek/pdf/CarbonDioxide.pdf

Good Luck!
                    ARGOS⁺⁺

[enahs]

Ohh I agree, it is not a real solution. It is a stupid solution, as helium is quite expensive. Just saying, if my life depended on it, I could make it work!   

[P]

Maybe the area of the pipe that is blocked is inaccessable  -  thus the need to reach the frozen part with a warm gas to melt/sublimate the blockage?

[ARGOS++]

Dear P;

That’s exactly why we talk about the important property of a high diffusion coefficient, like for He or H₂ for transport of both: of mater (CO₂ - away) and bring some heat to the dry ice.
And the reason for that is, we want heat the pipe as less as ever possible, and be inert at the same time, because we don’t know for what the pipe is used.

Good Luck!
                    ARGOS⁺⁺