In this experiment the objective is to determine what observable factors are changed in a chemical reaction and what factors remain constant.
Chemicals Used:
Part one calls for 50 ml hydrochloric acid (you will need to buy 2 of the linked to product,) and 8 grams of zinc.
You can also buy the Hydrochloric acid at someplace like lab or at a commercial cleaning supply company under the name “muriatic acid”, but you want it diluted to 3 M for this lab. I chose to buy it from lab.
Part two calls for 50 ml acetic acid (vinegar) and sodium bicarbonate (baking soda).
I bought these two items, only because I didn’t know that I had them in my pantry!
Equipment Used:
250 ml flask
Balloons
Balance – We didn’t have a balance, so we went on without it, but because we want to consider the Law of Conservation of Mass, it would have been a valuable tool to have.
Safety Considerations:
You are using acid this week so use proper safety precautions for hydrochloric acid! Please be sure to use goggles, gloves, and possibly some protective clothing.
You should do part one of this experiment outside.
Things Considered:
In an exothermic reaction energy is being released by the reaction, therefore the system becomes warmer.
In an endothermic reaction energy is being used by the reaction, so the system becomes cooler.
Watch the Experiments:
Here is a video of part one being demonstrated.
What Happened?
Here is an explanation of what happened in part one (that’s hydrogen gas in your balloon – be careful,) and part two (it’s just carbon dioxide in this balloon – your plants will like it.)
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| Ronnie used a funnel to get the zinc powder into the balloon. |
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| The balloon has to be securely over the mouth of the flask. |
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| We did part one inside, but the smell bothered us, so we moved outside. |
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| We were much safer doing part two outside, but it was harmless. |
this look cool to me