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Q & A: Baking Soda/Vinegar Balloons

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Most recent answer: 05/09/2012
On the vinegar and baking soda balloon project, how do you blow balloon up with these ingredients?
- Danielle Valentine (age 11)
The baking soda/vinegar balloons is a fascinating demonstration of acid base chemistry.

Vinegar is water with about 3 percent of a chemical called Acetic acid. Baking Soda is a compound called Sodium Bicarbonate, also known as Sodium Hydrogen Carbonate (NaHCO3), and is a base.

So the reaction occurs:

Acetic Acid + Sodium Hydrogen Carbonate ---> Water and CO2 and Sodium Acetate (or more specifically, aqueous sodium ions and aqueous Acetate ions, but evaporate the water away and you should get sodium acetate, a salt -- sodium acetate is used to de-ice airport runways. It has the property that dry sodium acetate emits heat when it dissolves in water).

CO2 (carbon dioxide) is the gas thatís produced and that expands the balloon. The trick of the project is to get enough CO2 produced and to make the seal between the container youíre mixing the baking soda and vinegar in sealed well enough so the CO2 doesnít leak out. It takes some pressure to inflate a balloon, so some CO2 may escape if the seal isnít tight.

Carbon dioxide is heavier than air, the balloon wonít float in the air, but will fall to the ground or stay on whatever itís placed on.

Jason (and Tom)

(published on 10/22/2007)

Follow-Up #1: baking soda balloon

Can baking soda and vinegar inflate a balloon?
- Anonymous (age 15)
Sure, the trick is to make sure that they donít mix too much before you get the balloon sealed off. You could try putting some vinegar in, twisting the balloon to seal that away a little, adding the baking soda, then quickly tying off the balloon. Then let the ingredients mix. Thereís not much to lose in trying.

Mike W.

(published on 10/22/2007)

Follow-Up #2: CO2 balloons

- Elizabeth Gusman (age 14)
One way is to pour a little vinegar into the balloon and then use a string or rubber band to seal off the little part of the balloon with the vinegar in it. Then pour in a little baking soda into the rest of the balloon. Now seal off the whole balloon by tying off its opening. Then open up the seal between the tip with the vinegar and the part with the baking soda. They should react, releasing CO2which will blow up the sealed balloon.

Mike W.

(published on 01/10/2008)

Follow-Up #3: Baking soda and vinegar

um im going a 5th grade sicence fair!!! and im wondering if the baking soda and vinegar is goin to be so bad that u need gogles??????????
- Katie (age 11)
Yes! It can get into your eyes.  Bad scene.


(published on 02/23/2008)

Follow-Up #4: vinegar plus baking soda reaction

If you put the baking soda in the balloon and carefully stretch the opening over the opening of a water bottle with vinegar in it, you can then dump the baking soda into the vinegar after the balloon is sealed so there's no mess. But my question is--is this an example of a changing state of matter or a change in substance?
- Clare (age 40)
Pittsburgh Pa
That sounds like a nice system for blowing up the balloon.

The acetic acid of course starts off as one ingredient in a liquid solution, vinegar. The baking soda starts off as a powder, which I guess is crystalline on a small scale. The combination leaves some new ions (e.g. Na+) in the solution and releases some gas (CO2). So it would certainly be called a chemical reaction, i.e. what you call a "change of substance." It also produces a lot of a different (gas) phase, so you could call it a "changing state of matter". There's no reason a process can't do both.

Mike W.

(published on 05/09/2012)

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