All gases have weight. However, different gases weight different amounts. Let's make our own gas balance to see how one gas measures up!
What you need:
- 1 wooden stick or rod, about 18 inches long
- 2 brown paper lunch bags
- 1 large glass
- 1/4 cup vinegar
- 2 tablespoons baking soda
- 1 Tack
What you do:
- Attach one paper bag to each end of the rod with the top of the bags open and facing up.
- Carefully place the rod on the tack with the tack in the center of the rod. Place this on the corner of a table so the rod swings like a balance.
- Mix the vinegar and baking soda together in the glass. Make sure you do this over a sink.
- As the mixture is bubbling up, tilt the glass over one bag. Do not let the liquid pour out of the glass. The balance will fall.
What happened?
When you mix baking soda and vinegar, a chemical reaction takes place that releases carbon dioxide. When you tilted the glass, the carbon dioxide being released from the reaction escaped from the glass and fell down into the bag.
All gases have weight. Carbon dioxide weighs more than most of the gas here on Earth, so the bag of carbon dioxide pushes down on the balance harder than regular air does.
You have probably seen a seesaw or a teeter-totter on the playground before. If an adult sits at one end and a child sits at the other, the seesaw will tip so the adult goes down and the child rises into the air because the adult is heavier. This experiment did the same thing, except that we used gases instead of people.
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