Thursday, November 11, 2010

Midterm Review Question #8

8) Explain the difference between chemical properties.  Describe some of the physical and chemical changes involved in cooking.

    -Produces matter different from original composition in a chemical change that can't be restored to                        
original state.

    -Can be observed and measured without changing substance's composition and can be restored to original state.

Cooking Example:
    -When baking a cake a key ingredient is baking soda which causes a chemical reaction enabling the cake to rise.  This is chemical because the cake can never be turned back into the same batter.


  1. Katherine overall I think your post was good and also correct but I think you could've elaborated a little more on your cooking example. For example you could say something about how in cooking the melting and boiling points are examples of physical properties and when food spoils, rots or burns these are considered to be chemical properties!

  2. Katherine what a great job!!

    I liked how you started off with the questions. Although it was a simple thing to do, it is important for the reader to be reminded on what he/she is going to be reading about. I enjoyed your concise explanations that were short yet to the point. Although I did like your cooking example, I also felt there was room for improvement. A few more examples who have been useful to answer the questions and, if possible, pictures would have added a nice creative touched when needed. Overall you have all the correct information needed to answer the questions. Excellent job!

  3. Thank you so much for the answers. They really helped me elaborate on my answers and think of good examples. Your blog was short and easy to read but still went over the main point of chemical and physical properties. The only thing I have to say is that it would have been nice if you added more examples (especially in your cooking examples). However, it was done well overall.

  4. Kathrine, it looks like you did a great job. I would however suggest that when you say Physical properties can be observed in such a way that the substance can be returned to its original state you should make the distinction between reversible and non reversible physical properties. As we know, there are some physical properties that can only be observed in a way that makes it difficult to return the substance to its original state, these observation do not require changing the composition of the substance so they are still considered physical properties, they are just not reversible.

  5. Great job, Katherine!
    Maybe you should mention the reversible and irreversible properties next time to avoid confusion.
    All in all, good job!

  6. Yes, I agree with a number of you. It will be important to remember reversible and irreversible and intensive and extensive because both of those also relate to chemical and physical properties.