Blowing Up Balloons

First, Lauren and I blew up a balloon by a non conventional method of baking soda and vinegar. This was in honor of Lauren's first science experiment when she was about 1. We put the stuff in the bottle and got her attention. When the balloon started expanding she was suprised and her attention was glued to that balloon. She also enjoyed it this time. I wasn't too worried about amounts so I used about a half cup of white vinegar (acetic acid) and a table spoon of baking soda. I might suggest using less baking soda as we had fiz going in the balloon with the carbon dioxide.







The next balloon was more for the adventurer in me rather than for Lauren. I am exited to report that it fills the balloon with a different gas that carbon dioxide. I did a couple trial runs with my friends and worked out a few bugs. Then onto the family reunion. I was hoping to make a balloon that floated for the kids. I thought I had it figured out by paying extra for helium quality balloons. I figured wrong. The gas still had too many impurities to be light enough to float. It only falls slowly. When I get one I will post it. The materials are simple: a glass bottle in a ice bath, about a tablespoon of Aluminum, wadded up foil is the easiest, and less than a 1/4 cup of Hydrochloric acid. The glass bottle is important. The reaction get incredibly hot. Although the acid doesn't react with it, I'm pretty sure the plastic would melt from the heat. Hydrochloric acid (HCl) has many names, it is sold commercialy as Muratic acid. You can buy it to clean brick or cement or in my case make a balloon that floats.

The last part was adult only. The danger level is still low, but I didn't want to be an inspiration to any aspiring pyromaniacs. Basicially I would have had two 9 - 10 year old boys who I didn't what to see it.

Nerd moment

Balloon #1

Vinegar is called acetic acid. Its pka a measure of the strength of an acid or base, is 4.76 so about half way between water and your stomach. Baking soda as we learned last time is sodium bicarbonate, a base. It also happens to be one of the most important molecules in your bodies buffering system. It again acepts a proton then splits into water and carbon dioxide. I know, a repeat from last time. I has sentimental value though.

Balloon #2

Aluminum, the third most abundant element in the earth, is very reactive and rarely found alone. Aluminum foil is usu only 92 - 96 % aluminum. Aluminum can have as much as a + 3 charge and therefore is very attractive to a negatively charged chloride ion. Chlorine (Cl) has a minus 1 charge. This makes aluminum chloride which is used in making both paint and anti perspiant. The excess hydrogen combines with itself to share each others electrons and moves to the gas form. The balloon then is filled mostly with hydrogen gas and should float because hydrogen is lighter than air, but the impurities such as acid vapor, a little aluminum chloride. It would be normal to worry about chlorine gas which is dangerous it can react with water in your lungs and turn back into hydrochloric acid which is bad for your lungs. It is the poison gas used in World War I. However as you see from the reaction below it is not produced in this case.

Chemical Reaction

2Al + 6HCl --> 2AlCl3 + 3H2

Some may argue that even though your not bubbling Oxygen gas (O2) in the reaction that there is minimal amounts there and you have a minor reaction taking place that would result in chlorine gas (Cl2(g)) I suppose yes, it is going on, but the amount of harmful chlorine gas being produce is not enough to detect without high tech instrumentation.

Chemical Reaction

4HCl + O2 (g) --> 2Cl2 (g) + 2H2O