Sciencemadness Discussion Board

BIGGEST BAKING SODA VOLCANO EVER

Acetic Acid - 4-9-2011 at 14:54

I just had another idea. It's like the simple baking soda and vinegar volcano, but on an insane scale. Instead of using a couple teaspoons of baking soda and 1 or 2 cups of vinegar, someone should do it with a 1/2 GALLON bottle of acid drain cleaner, and 12 POUNDS of baking soda.

H2SO4 + 2 NaHCO3 --> Na2SO4 + 2 CO2 + 2 H2O

This much sulfuric acid is found in a bottle of "Rooto Professional Drain Opener", and this amount of baking soda is sold at Wal-Mart for raising the pH of swimming pools.

34.2 moles of sulfuric acid react with 64.9 moles of sodium bicarbonate to give 4610 grams of sodium sulfate, 1170 mL of water, and 1558 liters of carbon dioxide. That's equal to a cube of gas almost 4 feet on a side. If you made your volcano in a cone shape like those demonstrations everyone has seen, I couldn't even imagine how high it would go.

Discuss.

The WiZard is In - 4-9-2011 at 15:07

Quote: Originally posted by Acetic Acid  
I just had another idea. It's like the simple baking soda and vinegar volcano, but on an insane scale.

Discuss.


Discuss?!

No-hum.


I let Rupert have your gift Faraday, but I remember being suspicious about the glee with which he received it. I have re-examined the book now, after the south pasture eruption (of which more later). I now note it is a book without an author. Suspicious to say the least. Its innocuous first page is, I now realise, mearly a ruse - a camouflage - as it is directly followed by various preparations of fulminating concoctions. It is, I must say, a thoroughly interesting book, but to someone like Rupert, a potential Armageddon of chemical and electrical mayhem is likely. As well you know Faraday, my son is highly resourceful. He and Hodges` son had contrived to order and have delivered one tonne each of iron filings and flowers of sulphur. In my name and without my knowledge. This must have been a week after receiving "The Young Mans Book of Amusement". The first inkling I had that mischief was afoot was a strong sulphurous smell, occasionally wafting in the breeze from the south pasture. Later that day, Hodges arrived in my lab with Maud the maid. Both were in a dreadful funk. Hodges exclaiming that a volcano was erupting in the south pasture, Maud maintaining that the devil himself had arrived. My first thought was that the pair of them had been at my Indian hemp plantation again, however this would not have accounted for Maud`s clothing, which appeared to have large monoclinic sulphur crystals attached to the posterior regions.

Upon arrival in the south pasture, I had to agree with them. It looked like an abomination of Lucifer. A carbuncle of perhaps twenty feet had risen from the pasture. The earth itself was riven, clods of earth and grass thrown aside, a hellish red glow emanating from deep fissures. Jets of steam and sulphurous gases noisily blew from its centre. Blue flames licked around the vents of the numerous fumeroles. Red liquid sulphur spilled from within, collecting and crystallising in yellow pools at our feet. Faraday, I was shocked.


http://www.lateralscience.co.uk/volcano/index.html

-----
Nicolas Lemery [1645-1715]
Cours de chimie, Paris 179, 1730.
Mellor 13, 387.


Acetic Acid - 4-9-2011 at 15:12

Now THAT is bad-ass.

The WiZard is In - 4-9-2011 at 15:26

Quote: Originally posted by Acetic Acid  
Now THAT is bad-ass.




Must-off smelled like one tooooooo!

Acetic Acid - 4-9-2011 at 15:27

XD

The WiZard is In - 4-9-2011 at 16:32

Quote: Originally posted by Acetic Acid  

34.2 moles of sulfuric acid react with 64.9 moles of sodium bicarbonate to give 4610 grams of sodium sulfate, 1170 mL of water, and 1558 liters of carbon dioxide. That's equal to a cube of gas almost 4 feet on a side. If you made your volcano in a cone shape like those demonstrations everyone has seen, I couldn't even imagine how high it would go.

Discuss.



How high it would go?! Light foaming - bubbles?!

A suggestion — throw in a box of bubble bath.

If you use vinegar — remember it is only a 4-5% solution of
acetic acid on a good day.

Acetic Acid - 4-9-2011 at 16:35

Bubble bath would indeed help. You'd probably need to throw in a lot though. Also, if I didn't mention it, it would be far better if the baking soda was pre-dissolved in water. Maybe you could dissolve the baking soda in the bubble bath? Vinegar is very dilute weak acid, but sulfuric acid is 96% by weight and always ionized. :P

Endimion17 - 4-9-2011 at 17:09

Acetic Acid, don't do it. It involves lots of acid. Be smarter than that.

[Edited on 5-9-2011 by Endimion17]

Acetic Acid - 4-9-2011 at 17:24

i wasn't planning to do it, but if you want to treat me like an idiot go right ahead.

Endimion17 - 5-9-2011 at 03:19

Quote: Originally posted by Acetic Acid  
i wasn't planning to do it, but if you want to treat me like an idiot go right ahead.


Jeez, what a diva! :o:D

I was not treating you as an idiot. You'd know if I did, trust me. :D
It was a simple and friendly advice which is always good to accept (I wouldn't mind the same treatmant).
In case you didn't know, huge piles of chemicals don't always react like small amounts, and neither this is always valid: (reaction of a big amount)=(reaction of a small amount) x N

That N is usually N<sup>k</sup>, where k>1.
It's a grossly simplified version of what happens in reality, but you get the point.

If you're going to work with huge amounts of vinegar, that's fine. Then the danger lies in vessel ruptures only.
Sulfuric acid... I wouldn't dare, unless I had access to a huge property with nothing on it and stand at a considerable distance...

ScienceSquirrel - 5-9-2011 at 03:34

I would use either glacial acetic acid diluted down to say 25 -50 % or the concentrated vinegar sold to the fish and chip trade at about 20 - 25% instead of sulphuric acid.
I reckon a couple of kilo scale would be OK.

blogfast25 - 5-9-2011 at 04:09

Quote: Originally posted by Endimion17  
That N is usually N<sup>k</sup>, where k>1.
It's a grossly simplified version of what happens in reality, but you get the point.



And this is based on?

Endimion17 - 5-9-2011 at 04:39

Quote: Originally posted by blogfast25  
Quote: Originally posted by Endimion17  
That N is usually N<sup>k</sup>, where k>1.
It's a grossly simplified version of what happens in reality, but you get the point.



And this is based on?


As I've said, it's simplified. I'm talking about huge piles of reactants, heat which can not escape. The reaction rate can depend on the sheer geometry of the vessel, its insulating properties, etc.

I tried, in the simplest form, explain how 500,000,000 grams of A and B won't react in the same manner as 500,000,000 small packets of 1 gram of A and B.

That's why ammonium nitrate is boring when you've got a handful, and horrific if a container with few tons of it is being licked by fire.
Not just ammonium nitrate. I believe we all know what happened at PEPCON.

[Edited on 5-9-2011 by Endimion17]

Bot0nist - 5-9-2011 at 05:24

This sounds interesting. Maybe a paste of bicarbonate and water as opposed to a solution. I don't believe it is spectacularly soluble in water (~96g per L) so a large volume of water would be needed.

I would like to see it done first on a molar scale and the observations like reaction time, temperature change, and visual description be keenly quantified and recorded. Then begin to scale up the reaction. Maybe .5 moles at a time, and determine the change of the reaction based on increased scale. Might make a good line graph even. That would be interesting.

BromicAcid - 5-9-2011 at 07:01

From my archives:
Quote:
One of my very first organic experiments involved my attempt to make diethyl ether. At the time I wasn't quite 14 years old but I had a lot of ambition. No, I didn't have any malicious purpose in mind, and it wasn't just a means to an end, it was the end. I just wanted to make some ether because my middle school chemistry book told me how and the reagents were accessible to me. So, I took a 3000 mL Erlenmeyer flask and charged it with 250 mL 96% H2SO4 and added about 50 mL ethanol. I put a big ol' rubber stopper in the Erlenmeyer it and cut a hole in it with a knife. From there I ran some tubing from it and into a 72 oz soda cup from the convince store where it spiraled down through some ice and out the bottom to collect in a beaker. Then I heated it on a electric camping stove (one of those portable oven coils) and waited.

It started bubbling and eventually I got some milky distillate (I figured the color came from the tubing. It ate the heck out of all the plastic and rubber, but what the hey, since when did I notice the obvious back then, most of it probably turned to ethylene anyway). I continued cranking on it and the stopper melted and started running down the inside walls of the Erlenmeyer, 'Time to turn it off' I thought. So I pulled the plug and yanked out the stopper which was hanging by the tubing over the acid and still melting. The mixture had stopped evolving gas so I assumed all the ethanol had been driven off. Wanting to dispose of it right away (and being environmentally conscious) I figured it would be best to neutralize it before tossing the mixture.

Thinking quickly I grabbed the only base that I had at my disposal, some sodium bicarbonate. It was still in the little orange box it came in from the grocery store. I grabbed the whole box and tipped it over the sulfuric acid. The sulfuric acid that was quite concentrated, the sulfuric acid still at about 200°C, the sulfuric acid that was about the blow up in my face as a huge chunk of the bicarbonate fell unbroken into the acid. The eruption from the flask was huge and I immediately threw myself back and landed on the ground, trying to get some distance. Miraculously the flask held in one piece, channeling the sulfuric acid into a torrential shower of acid rain. It came down, sizzling as it hit the ground but I was already scurrying toward the door of my house. Not knowing if I got anything in my eyes or on my face I immediately went to the sink and washed for about five minutes, then inspected myself. I got some on the arm of my shirt but nothing major. However, the picnic table did not fair so well, it was now severely charred in areas and the hot plate I had used to heat the mixture was quite the wreck too. A nice start for that picnic table which served me through nearly a decade more of my chemical mishaps.

Endimion17 - 5-9-2011 at 07:24

Also, Acetic Acid, do some reaction enthalpy math and you'll see why is vinegar cool for this experiment, and sulfuric acid isn't, and that's obvious if you've ever done this on a small scale and held the vessel in your hands.


(If my quick calculations are correct, the pun I inserted actually works:D)


ps: citric acid is cool, too. :)

[Edited on 5-9-2011 by Endimion17]

blogfast25 - 5-9-2011 at 07:47

Quote: Originally posted by Endimion17  
Also, Acetic Acid, do some reaction enthalpy math and you'll see why is vinegar cool for this experiment, and sulfuric acid isn't, and that's obvious if you've ever done this on a small scale and held the vessel in your hands.


(If my quick calculations are correct, the pun I inserted actually works:D)


ps: citric acid is cool, too. :)

[Edited on 5-9-2011 by Endimion17]


Reaction enthalpy for the neutralisation of sodium bicarbonate is actually positive (endothermic), the reaction appears to be entropy driven. It's a textbook class room experiment.

The reaction enthalpy shouldn't be much dependent on the type of acid used. There's an interesting thread on heat of neutralisation vs. type of acid on this forum, with lots of actual measurements made by myself.

With dilute H2SO4 I obtained a clear drop in temperature when neutralising sodium bicarbonate...

[Edited on 5-9-2011 by blogfast25]

Endimion17 - 5-9-2011 at 09:23

Quote: Originally posted by blogfast25  
Quote: Originally posted by Endimion17  
Also, Acetic Acid, do some reaction enthalpy math and you'll see why is vinegar cool for this experiment, and sulfuric acid isn't, and that's obvious if you've ever done this on a small scale and held the vessel in your hands.


(If my quick calculations are correct, the pun I inserted actually works:D)


ps: citric acid is cool, too. :)

[Edited on 5-9-2011 by Endimion17]


Reaction enthalpy for the neutralisation of sodium bicarbonate is actually positive (endothermic), the reaction appears to be entropy driven. It's a textbook class room experiment.

The reaction enthalpy shouldn't be much dependent on the type of acid used. There's an interesting thread on heat of neutralisation vs. type of acid on this forum, with lots of actual measurements made by myself.

With dilute H2SO4 I obtained a clear drop in temperature when neutralising sodium bicarbonate...

[Edited on 5-9-2011 by blogfast25]


Exactly, but I used pure acid for calculations. Forgot about that, thx.
Nevertheless, best heat absorption is with vinegar, and sulfuric acid, no matter how dilute, can't evaporate or break down. Skin will omnomnom vinegar, but it will get omnomnomed by the sulfuric acid. That's why it leaves holes in lots of materials even if it's very dilluted. I know what would happen. There would be a huge volcano, acid spraying everywhere, and someone would forget to wash completely in the shower. Voila, chemical burns. Itching and redness, but those are chemical burns.

That's why I recommend vinegar or citric acid. But the danger doesn't stop there, with benign chemical reactions. There are always dangers involving high pressures, projectiles etc.

blogfast25 - 5-9-2011 at 10:35

To be sure my memory served me well, I’ve just run a test with NaHCO3 + ½ H2SO4 === > ½ Na2SO4 + H2O + CO2

8.4 g (0.1 mol) of NaHCO3 were transferred into a 300 ml Dewar flask and 50 ml DIW added. This was allowed to stabilise. 50 ml of 1 M H2SO4 (0.05 mol H2SO4) were measured out and allowed to stand.

30 min later the bicar measured at 14.1 C, the acid at 16.6 C, the average (T1) being 15.4 C.

All the acid was the slowly in small aliquots added to the bicar, avoiding overflow due to fizzing. The resulting solution reacted neutral and after stabilising the temperature inside the flask (T2) was 13.3 C, so ΔT = - 2.1 C.

That corresponds to a (very approximate) value of ΔH ≈ + 9 kJ/mol for:

NaHCO3(aq) + ½ H2SO4(aq) === > ½ Na2SO4(aq) + H2O(l) + CO2(g)

Quote: Originally posted by Endimion17  
Nevertheless, best heat absorption is with vinegar, and sulfuric acid, no matter how dilute, can't evaporate or break down. Skin will omnomnom vinegar, but it will get omnomnomed by the sulfuric acid.


I'm not convinced that in comparable circumstances use of acetic instead of sulphuric acid will lead to a higher ΔH, I might put it to a test...

'omnomnom'??

[

[Edited on 5-9-2011 by blogfast25]

Endimion17 - 5-9-2011 at 18:39

Quote: Originally posted by blogfast25  
To be sure my memory served me well, I’ve just run a test with NaHCO3 + ½ H2SO4 === > ½ Na2SO4 + H2O + CO2

8.4 g (0.1 mol) of NaHCO3 were transferred into a 300 ml Dewar flask and 50 ml DIW added. This was allowed to stabilise. 50 ml of 1 M H2SO4 (0.05 mol H2SO4) were measured out and allowed to stand.

30 min later the bicar measured at 14.1 C, the acid at 16.6 C, the average (T1) being 15.4 C.

All the acid was the slowly in small aliquots added to the bicar, avoiding overflow due to fizzing. The resulting solution reacted neutral and after stabilising the temperature inside the flask (T2) was 13.3 C, so ΔT = - 2.1 C.

That corresponds to a (very approximate) value of ΔH ≈ + 9 kJ/mol for:

NaHCO3(aq) + ½ H2SO4(aq) === > ½ Na2SO4(aq) + H2O(l) + CO2(g)


It's cool that you performed this experiment. Mind that glass Dewars are not really the type of vessel for doing calorimetry with such small amounts of liquids and that small expected change of enthalpy. Thick styrofoam bottle would be better. But it seem the error wasn't too great, and that's great.


Quote:

I'm not convinced that in comparable circumstances use of acetic instead of sulphuric acid will lead to a higher ΔH, I might put it to a test...

I'm not sure, too, but I remember that it really cools the mixture down.


Quote:

'omnomnom'??

Is it possible that you've skipped this part of teh internets? :D click

[Edited on 6-9-2011 by Endimion17]

hkparker - 5-9-2011 at 18:51

You can gently fuse sodium carbonate and citric acid and it will not react noticeably until it gets wet. I know this because I did it for my highschool's drama team.

As a prop, they needed a tablet they could drop into a grad full of pure water that would cause the water to bubble and still be safe to consume. I was friends with one of the kids in the play and he asked me, knowing I was into chemistry, to create something like that.

I mixed citric acid and sodium carbonate in a clean steel pan and gently heated over a flame while stirring, and the mixture became sticky and bubbles a bit. It was still cool enough to touch so I took some out and squeezed it into a small cylinder shape.

Worked perfectly, bubbled well, and the resulting solution as it bubbled was close to neutral so I told them I wouldn't drink much (as it also tasted not too great) but it would be safe to consume, just sodium citrate solution.

Endimion17 - 6-9-2011 at 03:19

hkparker, but he wants a volcano, not a stable source of CO2. :D

Anyway, that's a cool method. I've tried it years ago and it works great. The acid is a monohydrate so it all blends really nice. It's safe to consume in small quantities. Larger quantities are not really recommended because Na+ is highly osmotic. If there's ice, and the citric acid is in excess but everything is rather dilluted, it can be refreshing and tasty.

blogfast25 - 6-9-2011 at 04:05

Quote:
Quote: Originally posted by Endimion17  
Mind that glass Dewars are not really the type of vessel for doing calorimetry with such small amounts of liquids and that small expected change of enthalpy.

Quote:

I'm not convinced that in comparable circumstances use of acetic instead of sulphuric acid will lead to a higher ΔH, I might put it to a test...

I'm not sure, too, but I remember that it really cools the mixture down.



The Dewar is part of my electrical compensation calorimeter, although here I didn't bother with the compensation.

I may do the acetic acid one later on.

Update:

I repeated the test above but with 0.1 mol NaHCO3 and 0.035 mol (7.4 g) of citric acid (H3Ct, I used the monohydrate form), dissolved in 50 ml of water.

The bicar (after stabilising) clocked in at 13.0 C, the acid at 14.6 C, so T1 = 13.8 C.

Adding the acid to the bicar resulted in the ubiquitous fizzing, albeit markedly slower than with H2SO4 (1 M). After adding all the acid and stabilising I got an end temperature of 9.9 C, so ΔT ≈ - 3.9 C, markedly higher than with sulphuric acid (- 2.1 C). This corresponds (very approximately) to a ΔH ≈ + 16 kJ/mol for:

NaHCO3(aq) + 1/3 H3Ct(aq) === > 1/3 Na3Ct(aq) + H2O(l) + CO2(g)

Although no electrical compensation was applied and no replicas were made, the difference between sulphuric (+ 9 kJ/mol) and citric acid (+ 16 kJ/mol) in terms of Reaction Enthalpy appears strongly significant. I wonder why that is…

Since as I used food grade products I took a sip of the resulting ‘fizzy drink’ and it’s not very nice: reminiscent of Alka Sentzer actually. Citrates, off the top of my head, are used in Jewish cooking (citric acid is available as Kosher grade).



[Edited on 6-9-2011 by blogfast25]