tag:blogger.com,1999:blog-7330736284861072065.post3453399310979940048..comments2022-03-29T07:09:14.856-04:00Comments on Confessions of a Homeschooling Mom: Chemistry for Kids, Part 5: Endothermic & Exothermic ReactionsKim HBhttp://www.blogger.com/profile/18351250611654842939noreply@blogger.comBlogger9125tag:blogger.com,1999:blog-7330736284861072065.post-49569472203854176732012-11-13T21:19:12.579-05:002012-11-13T21:19:12.579-05:00Listing this link strictly as an FYI, I found this...Listing this link strictly as an FYI, I found this recently and wanted to share: http://antoine.frostburg.edu/chem/senese/101/thermo/faq/exothermic-endothermic-examples.shtmlKim HBhttps://www.blogger.com/profile/18351250611654842939noreply@blogger.comtag:blogger.com,1999:blog-7330736284861072065.post-56471310034090558012012-11-13T21:12:26.228-05:002012-11-13T21:12:26.228-05:00Thanks for your comment. It was hard to find good,...Thanks for your comment. It was hard to find good, consistent info on this topic so I honestly did the best with what I had! I appreciate your input and will refer readers to your comment for clarification. With regards to the Mentos, the Mythbusters video in one of my previous comments does say the reaction manufactures additional CO2 (other than what's already in the soad) and the excessive presence of CO2 causes the explosion. Maybe there's a difference of opinion on what is actually happening??<br /><br />I also appreciate your positivity, it's encouraging where I need it most;^))Kim HBhttps://www.blogger.com/profile/18351250611654842939noreply@blogger.comtag:blogger.com,1999:blog-7330736284861072065.post-57985931515335828772012-11-13T10:08:20.937-05:002012-11-13T10:08:20.937-05:00Just a comment on your first example:
Melting ice ...Just a comment on your first example:<br />Melting ice is an endothermic process, but not an endothermic reaction. It is not classified as a reaction because there is no change in the composition of the substance. <br />Ice is water in solid state, when it melts it changes its state to liquid, but it is still water (H2O). Melting is a physical change. Melting requires energy, so it is an endothermic physical process.<br /><br />About the soda and mentos, I wouldn't say is an exothermic reaction, un less it releases energy in the form of heat (or light). In fact nobody is sure if the explosion is entirely a physical process or if there is a reaction involved. The CO2 is already in the soda. It is not manufactured. What is manufactured is the size of the bubbles, that need to grow big enough to break the surface tension of water. Its better explained here: http://en.wikipedia.org/wiki/Mentos_eruption<br /><br />The other examples are very nice examples. Congrats for homeschooling! Nothing better than the children being close to their parents! I would do it myself if I could.Akirahttps://www.blogger.com/profile/10126512854868537084noreply@blogger.comtag:blogger.com,1999:blog-7330736284861072065.post-1326526311271036232012-10-11T08:49:50.061-04:002012-10-11T08:49:50.061-04:00You are awesome! Thanks so much for your helpful t...You are awesome! Thanks so much for your helpful tips. Kim HBhttps://www.blogger.com/profile/18351250611654842939noreply@blogger.comtag:blogger.com,1999:blog-7330736284861072065.post-24719334250517155142012-10-11T07:46:52.415-04:002012-10-11T07:46:52.415-04:00A way to get the sodium acetate is best done as yo...A way to get the sodium acetate is best done as your link suggests, but continue to reduce liquid once film starts to appear. making sure you scrape any crystals that form round edge of pan back in to liquid. once its about 50 ml and has free floating crystals in liquid seal jar and place in fridge. <br />leave to cool and harvest any crystals that form. <br />the crystals are acetic acid but need reconstituting with boiling water (pref distilled). it only need a little water to reconstitute. let this chill in fridge and you should have a usable form of hot ice<br /> Anonymoushttps://www.blogger.com/profile/14914489351947392074noreply@blogger.comtag:blogger.com,1999:blog-7330736284861072065.post-18200813775501811492011-04-11T19:52:41.546-04:002011-04-11T19:52:41.546-04:00I don't think you can use OJ because it's ...I don't think you can use OJ because it's not pure citric acid. Vinegar will probably do if you don't have it and need a substitute. The only issue is, vinegar tends to bubble and foam A LOT whereas citric acid just bubbles mildly (if you add a little at a time) and allows the solution to remain clear so you can observe the temp change without getting all messy.<br /><br />I'm not sure why the reaction is classified as exothermic because I was not close enough to the geyser to feel any heat given off inside the bottle. If I find something,I'll let you know. I don't mind the questions;^)Kim HBhttps://www.blogger.com/profile/18351250611654842939noreply@blogger.comtag:blogger.com,1999:blog-7330736284861072065.post-35481789048943875812011-04-10T11:39:56.440-04:002011-04-10T11:39:56.440-04:00how is this related to exothermic reactions? i wan...how is this related to exothermic reactions? i want some sort of experiment/demonstration for my class to understand exothermic reactions better. <br /><br />oh and for the endothermic reaction, can orange juice be used for citric acid? i tried this myself and i couldn't really feel the reaction..maybe i used too much baking soda than citric acid? sorry for all these questions but it would be great if you answered them. :)<br /><br />thanks so much!Anonymousnoreply@blogger.comtag:blogger.com,1999:blog-7330736284861072065.post-65128265766514448952011-04-09T21:09:18.644-04:002011-04-09T21:09:18.644-04:00Sure, if you're looking for why it works, see ...Sure, if you're looking for why it works, see this video and it will help with the visualization. http://www.youtube.com/watch?v=LjbJELjLgZg&feature=related Basically, there are many different spots on the candy where CO2 can be manufactured and when combined with the soda and all its CO2, this creates an eruption since the bottle can't contain all the gas. All the CO2 gas wants to do is escape and escape it does! Let me know if this answers your question or if you have more.Kim HBhttps://www.blogger.com/profile/18351250611654842939noreply@blogger.comtag:blogger.com,1999:blog-7330736284861072065.post-44686705615040606232011-04-09T17:26:55.867-04:002011-04-09T17:26:55.867-04:00can you give me an explaination for the mentos and...can you give me an explaination for the mentos and soda experiment? thanksAnonymousnoreply@blogger.com