Lesson 11:
Determining if a chemical change has occurred by observation of generation of heat.
Supplies:
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEjs3XSQZTXvf98ihzj8yhoqcQh3kzlxyjbD3Ck2AOZd9ws28-INGlMNkYI5Q13VHu0pxj9GsklBEwXfcKQ-Q7CGDTEotL4kODuUrstsVlpbLnjm65ccug3zrlhsd6Euj23jKPm_pX0Q1PA/s320/PICT0001.JPG)
1 tsp yeast, 1/4 cup hydrogen peroxide, stirring stick, thermometer
Record beginning temp of the peroxide (67 degrees)
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhJV1NcmLyEeoCsEkmvXU-L98VS01-8Esa2oPyjpQn3ImUv7BVP2J_8kThxTrIVl2du8lBGFPqFWGn82u3AVuwcb89mzrBsjAqW7FBH_3h8zX87KmWDIOf5s5SI8Gmkq7K_8DPmXnJf7Sg/s320/PICT0011.JPG)
Mix yeast into the peroxide and stir
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEiZl-zkWa7cAVo2lofjD2JYLVUGcmz2CXTakperKtJK6B4HCor9KgP7e3pk6OO233tjFrJ5ooE3bL1PVkCZK-cx_M9Q5kWxj_iIETpMCw-VmuoZ_rQVslPCY_DyY4bpAS32jdR0VwRMd4k/s320/PICT0003.JPG)
The mixture begins to bubble and fizz....another sign that a chemical reaction is taking place. If you keep your hands on the outside of the bowl you can feel it begin to heat up.
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEhYKBJAvINHhpoAay6B9OYxwHGfHbO9t0aCG1eiIVrRJcfArW2LCIZPhgcj3Xd33U4erzHW4h-7o-qLlfwDmpF6p4w0DIWzUZTPKEhAfjfGQxPv1_m7nIMeX-tBPMZPs5bxpapvb67HKrc/s320/PICT0006.JPG)
Record ending temperature (90 degrees)
![](https://blogger.googleusercontent.com/img/b/R29vZ2xl/AVvXsEgo6-eKPXJfDBKwPAhVe-CCVkXBeGMK295y_DZMaf-hREbwxO_m_7puqw3lAlgbTQ3dJzx8UsJasUz8nBeOnslUlFnizMdOQKDke0lVh-X3hK3SyBIdXqA-4EC-POnl43UNOQoGKW0CIV8/s320/PICT0010.JPG)
They were actually pretty amazed by this one. I keep listing the ways to tell if a chemical reaction has taken place....they've seen the bubbling, they've seen the gas given off.....I guess they didn't really believe that heat could actually be created by just mixing 2 things.
I like this experiment oh how I wish I had this on Tuesday. :)
ReplyDeleteThanks for sharing we may go back and review and do this one right away. :)
Science experiments are always my favorite. You have a really cool blog!
ReplyDeleteVERY cool! I was thinking of starting Chem next term....what curriculum do you use? I love your hands on approach. I especially love that you tackle chem with young ones. It truly develops a love for science and a taste for curiosity.
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