2012/10/30

This week's assignment...

I just looked over the assignments that have been handed in so far, and I have a couple additional notes:

1. For each combination that reacted during the first week of the experiment, write a balanced chemical equation.  For reactions that formed complex ions, you can just note that the product of the reaction is “complex ion”.  Organize your reactions clearly in the order they appear in the lab manual, starting with all the reactions involving Ni(NO3)2(aq), then all the reactions involving Pb(NO3)2(aq), etc.
>>If a combination did not react, you do not have to write a reaction. You can write "full formula/molecular equations" or net ionic equations, it's your choice for this experiment.
>>DO NOT WRITE YOUR CHEMICAL EQUATIONS AS ONE BIG PARAGRAPH!! The point of organizing them is to make them easier for you to write them all and for me to follow/read/grade them. If you write them as a massive block of text, I will not read them, and you probably won't earn many points. One equation per line, with appropriate subscripts and/or superscripts, state labels, parentheses, etc.
>>"in the order they appear in the lab manual" is not a joke or a suggestion. If you do not organize your chemical equations in the correct order, I will not spend much time hunting through your randomly-ordered equations to try to find them all. I will assume they are not there and you probably won't earn many points.

2. Identify the contents of each of your unknowns with a brief explanation.  For example, “Unknown M4 contained phosphoric acid because it generated heat when reacting with bases and formed a precipitate with transition metal ions.”
>>Each set of unknowns had a letter AND a number associated with each sample. If you do not identify each unknown with a letter AND a number, it is wrong.

If you've already handed in an assignment and would like to fix some of these problems (that would be a really good idea...), you can turn in a revised assignment. If you choose to turn in a revised assignment, you must very clearly and obviously write or type "PLEASE GRADE THIS ASSIGNMENT AND DISCARD THE PREVIOUS ONE" on your assignment (you might even want to use a highlighter...). If you do not clearly and obviously indicate that you want the "new" assignment graded, I will grade the first assignment that was submitted.

No comments:

Post a Comment