Cracolice 2/e Ch 2.
Answer key
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Abbreviation: PT = periodic table.
Total points: 9.
Of course, points are not relevant to an informal, self-help quiz. But I put point information and "rules" on some quizzes, just to give you an idea of how things would look on a test.
Quiz is "closed book" except for PT & calculator. If a question requests an explanation, there may be no credit unless you have provided an explanation.
1. (3 pts.; 1 pt. per part) We have discussed the distinction between the macroscopic and particulate views of matter. We often see the macroscopic (the big picture), but attempt to explain it in terms of its particulate nature. We might make some analogies...
a. If we consider a library to be macroscopic, the particulate view would focus on the _________.
I encourage you to check your answer for part a before spending too much time on the remaining parts. Remember, you should have a reason for your answer.
b. If we consider a classroom to be macroscopic, the particulate view would focus on the _________.
c. If we consider a classroom to be a particle, the macroscopic view would focus on the _________.
2. (2 pts.; 1 pt. per part; no credit without explanation) For each of the following reactions, tell whether it is a chemical change or a physical change. Briefly explain how you can tell.
a. solid iron + oxygen gas --> iron(III) oxide (a solid)
[In chemical symbols, that would be... 4 Fe (s) + 3 O2 (g) --> 2 Fe2O3 (s)]
b. solid iron --> liquid iron
[Fe (s) --> Fe (l)]
3. (1 pt., no credit without explanation) Consider the product side of the reaction in #2a, above. Does this show a compound or a mixture (or neither or both)? Explain.
4. (2 pts.) Sketch a particulate diagram to show what happens in the reaction in #2a, above. The particulate diagram should show what the chemicals are, and should be quantitatively correct. I suggest you use Fe as the symbol for an iron atom, and O as the symbol for an oxygen atom. Since the diagram here is about specific chemicals, why not use their common symbols? (The emphasis here is on a chemical reaction; there is no need to try to show the phases in your particulate diagram in this case.)
5. (1 pt.) You might have suspected that the next question would be to draw a particulate diagram for the process shown in #2b, above. However, that is a bit tricky. Instead, let's ask a related question: Consider 12 atoms of an element -- any element; call it X. Make three particulate diagrams to show what this set of 12 X atoms would look like as a solid, as a liquid, and as a gas.
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Last update: August 29, 2019