Making a helium balloon

The secret to making balloons fly!

Who isn’t cheered by the sight of these col­or­ful float­ing orbs? But since he­li­um bal­loons are an ex­pen­sive in­dul­gence nowa­days, you might won­der whether you can make he­li­um bal­loons at home. So can you? Let’s get right into it!

[Deposit Photos]

He­li­um is a non-tox­ic, monatom­ic gas that holds sec­ond place in Mendeleev’s pe­ri­od­ic ta­ble of el­e­ments. It is col­or­less, odor­less, and much lighter than oxy­gen and car­bon diox­ide.

While oxy­gen’s molec­u­lar mass is 32, and car­bon diox­ide’s is 44, he­li­um’s molec­u­lar mass is an in­cred­i­bly light 4. So bal­loons filled with the monatom­ic gas can fly, while car­bon diox­ide weighs them down. The lighter the bal­loon’s gaseous con­tents, the greater its chances to fly.

Where you can find he­li­um bal­loons

The he­li­um used in bal­loons is ob­tained by deep-freez­ing nat­u­ral gas. Un­for­tu­nate­ly, since it’s im­pos­si­ble to make he­li­um via a chem­i­cal re­ac­tion, it would re­quire a con­sid­er­able sum of mon­ey to blow up he­li­um bal­loons your­self. If you need a he­li­um bal­loon and want to in­flate it at home, it’s best to buy a spe­cial can­is­ter of he­li­um. But there are many oth­er in­ter­est­ing ex­per­i­ments that you can per­form with bal­loons that will lead you to new chem­istry dis­cov­er­ies.

A bal­loon filled with soda and vine­gar

In­ter­est­ing­ly, a re­ac­tion be­tween bak­ing soda (NaH­CO₃) and vine­gar (CH₃­COOH) re­leas­es a great deal of car­bon diox­ide. Of course, car­bon diox­ide’s atom­ic mass is too great to al­low the bal­loon to fly, but the ex­per­i­ment is fas­ci­nat­ing and can eas­i­ly be done at home.

Balloons filled with CO₂ [Flickr]

This is a handy trick to get a child in­ter­est­ed in chem­istry! The process of blow­ing up the bal­loon with a bot­tle will pique their in­ter­est in sci­ence, and per­haps their de­sire to con­tin­ue mak­ing their own dis­cov­er­ies.

You’ll need:

  • acetic acid, which can be found in any kitchen (there are dif­fer­ent types of vine­gar, but prac­ti­cal­ly any will do);

  • bak­ing soda;

  • an emp­ty 1.5-liter bot­tle or a flask;

  • gloves;

  • bal­loon.

This is a sim­ple trick to do at home – even a child can do it. But be sure to wear rub­ber gloves! Vine­gar, es­pe­cial­ly strong vine­gar, can cause a mild chem­i­cal burn. Just keep in mind that bak­ing soda or soap will neu­tral­ize the acid.

Any and all ex­per­i­ments in­volv­ing risky chem­i­cal sub­stances should be con­duct­ed un­der adult su­per­vi­sion.

Pour two tea­spoons of bak­ing soda into your bal­loon, and pour half a cup of acetic acid into the bot­tle. Don’t add too much soda! In­sert the bot­tle­neck into the bal­loon’s neck and straight­en the bal­loon: the bak­ing soda in the bal­loon will fall into the bot­tle and meet the vine­gar. An in­tense re­ac­tion will be­gin, re­leas­ing CO2 and mak­ing the bal­loon in­flate. If the re­ac­tion is too weak to in­flate the bal­loon, add more vine­gar and bak­ing soda, but don’t shake the so­lu­tion.

This method is con­ve­nient if you find it dif­fi­cult to blow up a bal­loon.

Fly­ing with­out he­li­um

You can use this method to in­flate a bal­loon that will, in fact, fly. Though this ex­per­i­ment does work, it pos­es a risk of fire, so per­form it out­doors. Gog­gles, a lab coat, and gloves are non-ne­go­tiably nec­es­sary pre­cau­tion­ary mea­sures.

Keep in mind that the sub­stance re­leased from the so­lu­tion ob­tained con­tains hy­dro­gen, which is ex­plo­sive! Not only should you do this ex­per­i­ment out­side, but you also should nev­er store such bal­loons at home: the hy­dro­gen will ex­plode if it comes into con­tact with a spark. Click here to find out which ex­per­i­ments with hy­dro­gen you can do at home. You should also be care­ful dur­ing the ex­per­i­ment it­self: if you add too much foil and clean­ing agent, or if you shake the con­tents care­less­ly, you can burn your­self on the flask. Don’t breathe in the gas that is re­leased over the course of the ex­per­i­ment. You’ll need:

  • alu­minum foil;

  • room-tem­per­a­ture wa­ter;

  • a bal­loon;

  • sodi­um hy­drox­ide;

  • a glass flask.

You may also need some­one to help you. A good source of sodi­um hy­drox­ide (or an­oth­er strong al­ka­li) are the al­ka­line de­ter­gents usu­al­ly sold in hard­ware stores.

First, make a few small foil balls. Pour the clean­ing agent into the flask and add some wa­ter. Add the foil balls you’ve made. Don’t shake the so­lu­tion! You’ll cause a vig­or­ous re­ac­tion – the bal­loon will in­flate, but the wa­ter va­por that re­sults from this re­ac­tion will con­dense in­side the bal­loon and weigh it down, pre­vent­ing the bal­loon from fly­ing.

Balloon filled with hydrogen [Flickr]

If you don’t shake the so­lu­tion, the re­ac­tion will take place slow­ly, but the con­den­sate in­side the bal­loon will run back into the flask and no longer weigh the bal­loon down. At­ten­tion plus pa­tience will yield much bet­ter re­sults! And it will be worth it in the end: your bal­loon will fly as though filled with he­li­um!