Hello fellow scientists. Before me you see
two common household items – vinegar and baking soda. What do we know about vinegar? Let’s
make some observations. It’s a clear liquid… It’s good on salads… It tastes sour… What do we know about baking soda?
It’s a white powder… It’s bitter….
You can use it to deodorize your carpets…. It comes in handy in BAKING. That’s why
they call it BAKING soda. What do you think happens if you MIX vinegar
and baking soda? Vinegar is an ACID, acetic acid. Baking soda
is a BASE, which is kind of the opposite of an acid. When you mix an acid and a base,
something DRAMATIC usually happens. We’d better get prepared. I’m wearing my lab coat, I’m putting on my safety goggles – I’m ready. I will add the vinegar to the baking soda. And I will observe! OBSERVE WITH ME! Well, that was interesting. I saw bubbles.
I heard hissing. What does that mean? Think. Think think think. With your brains! I think that means a GAS
was released. Based on my extensive knowledge of chemistry, I know that it was CARBON DIOXIDE.
You know carbon dioxide. We breathe it out every time we exhale! like that. And that.
There goes some more. If I mix vinegar and baking soda together
in this bottle, I can CAPTURE the gas being released in a balloon. It may even be powerful
enough to blow the balloon up! First I’ll pour a little vinegar into the bottle, and I’ll add a tablespoon of baking soda into my balloon. ….Stretch the balloon over the bottle, …And now dump in the baking soda. Well, looky here. We have a balloon filled with carbon dioxide! … What am I supposed to
do with a balloon filled with carbon dioxide? I guess we could feed it to some plants and
they can do photosynthesis. We’ll talk about that another day. Now listen carefully. Some people might call
what we just did an experiment. But it wasn’t a REAL experiment. That was just a DEMONSTRATION.
An EXPERIMENT is part of the SCIENTIFIC METHOD, where you ask a QUESTION about HOW SOMETHING
WORKS. You gather as much information as you can about the subject. Then you try to PREDICT
the answer to the question. That is, you make a HYPOTHESIS based on what you know (sort
of like an educated guess). Then you TEST to see if your hypothesis was correct – that’s
the EXPERIMENT part. For example. What if I wanted to find out how to make more gas?
Do I add more vinegar? More baking soda? Do I heat it up? What’s your hypothesis? Tell
me below in the comments. Okay, that’s all the time we have for science today. See you
next time. Bye.