1. A. Compare the color of the three coins—untreated (the control), heated in the zinc solution only, and then heated in the zinc chloride solution and then on a hot plate.
a. The untreated penny is bronze colored, like a regular penny. The penny that just the received the zinc chloride treatment changed into a silvery shade. The penny that was treated with the zinc chloride and the hot plate became a pretty, shiny golden-yellow color.
B. Do the treated coins appear to be composed of metals other than copper? If so, explain.
b. Yes the pennies that were treated seem to be composed of another metal besides copper because of the difference in color.
2. If someone claimed that a precious metal was produced in this investigation, how would you decide whether the claim was correct?
a. We could test the metal with other solutions to see if it has high reactivity, and if it is not we could assume it is a precious metal.
3. Identify at least two practical uses for metallic changes similar to those you observed in this investigation.
a. The different colors produced could be used for decoration, or it could be melted down even more and molded to form utensils.
4. A. What happened to the copper atoms originally present in the treated pennies? Provide evidence to support your conclusion.
a. The copper atoms in the treated pennies were heated and mixed more evenly with the zinc causing a reaction and a color change. They are not destroyed, as it appears, but the reaction caused it to have a different appearance.
B. Do you think the treated pennies could be converted back to ordinary coins? If so, what procedures would you use to accomplish this?
b. No, I don’t think they would be able to convert back to their original state.
4.b. is incorrect because it can be changed back by putting it on the hot plate for a longer amount of time.
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ReplyDeletehow dare you this helped me cheat >:(
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