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Monday, May 31, 2010

Endothermic and Exothermic Reactions

On Friday 28th, after showing our colored periodic tables to ms.D, we were told that we are going do a lab about exothermic and endothermic reactions. We had to read about them for that day, so everybody already knew what they were.
For you people that had the shame of missing our class, or just aren't part of it (which is also a shame), here is a definition of both:

- Exothermic Reaction: A change in which energy (or NRG) is released.

- Endothermic Reaction: A change in which energy is taken in.

So, the purpose question was "How do measured temperatures show the difference between an exothermic and endothermic reaction?"

In the actual lab, we mixed Yeast with Hydrogen Peroxide, and Baking Soda with Vinegar.
Yeast and Baking Soda being the Solutes, and Hydrogen Peroxide and Vinegar being the Solvents.
After consulting it with ms.D, we decided that the independent variable of the lab was temperature, and that the dependent variable of the lab were the endothermic and exothermic reactions.

The result of the first experiment was that Yeast and Hydrogen Peroxide became instantly very bubbly and hot, and stunk like rotten bread.

The second experiment was a bit slower, as the chemical reaction took longer to occur. The result was lots of bubbles and the container becoming cold.

All of the experiments went without any injury and everyone left with good data.
The whole lab is in our Chemistry Packet, so check it out!

If you still don't understand the difference between endothermic and exothermic reactions, here is a link showing some simple examples of them.

Thank you for reading my scribe post. I hope you enjoyed it and that it was helpful.

The next scribe is... well, I can't find the list of available scribes, so I'll have to ask ms.D.


  1. Hey Daniel,
    Your post was great you introduced the new lab very well. And I liked how you gave the definitions of endothermic and exothermic reactions! Your pictures were great and I think they are very neat. Although, there are some things you could improve on. You could have attached the URL to the directions of the lab. You could have also put up the partners or groups of the lab! All in all, your post was great!!

  2. Hey! Nice post! Are you the last scribe? 'Cause if you aren't then you forgot to add the next scribe. Tough I'm guessing your the last one. Your post was great and used colors well. (Though why was "Baking Soda" a different color than the other Solutes in the first mix?)
    I liked the pictures, though, it would've been halpful to have some examples of endothermic and exothermic reaction with the description, and not just on the link.
    But overall, great post!

  3. Daniel - Nice Scribe Post. You have chosen a clear font, but in places it is too small, too light or is hard to follow due to the combination of print + pictures. Nice choice of pictures - although captions may have helped. Great link to common Exothermic/Endothermic Reactions. Plus your definitions of these two changes are very clear. However, for the lab you have gotten the IV and DV incorrect. I think you could have gone into more detail about the lab as well.Finally, you have no real-life relationship for this post, which was the newest requirement for blogging this quarter. Make sure in the future to follow all directions of projects. Overall, not bad. ~Ms. D.

  4. Hey Daniel! I liked your scribe very much. It was nicely layed out and I liked your pictures. Sometimes the font was a little too small, though. I think you could have checked with Ms. D about the next scribe before scribing yourself. I also think you could have given some definitions, for example telling the readers what Hydrogen Peroxide is. Overall, though, I liked your scribe.

  5. Hey Daniel,
    I thought that your blog post was great and included lots of detail. But one thing you could work on was actually puting an attachment or URL for the lab directions. Your science was great because it allowed me understand endothermic and exothermic reactions again. Overall you did well.