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week_one_exercises.docxWeek One Exercises
Complete the following exercises from Introductory Chemistry:
· Exercise 22 in Ch. 1=
22. A chemist decomposes several samples of water into hydrogen and oxygen and weighs (or more correctly “measures the mass of”) the hydrogen and the oxygen obtained. The results are tabulated as follows.
Sample Grams Grams
Number of Hydrogen of Oxygen
1 1.5 12
2 2 16
3 2.5 20
(a) Summarize these observations in a short statement.
Next, the chemist decomposes several samples of carbon dioxide into carbon and oxygen. The results are tabulated as follows.
Sample Grams Grams
Number of Carbon of Oxygen
1 0.5 1.3
2 1.0 2.7
3 1.5 4.0
(b) Summarize these observations in a short statement.
(c) Formulate a law from the observations in (a) and (b).
(d) Formulate a theory that might explain your law in (c).
· Exercise 117 in Ch. 2 =
117. Block A of an unknown metal has a volume of 125 cm3. Block B of a different metal has a volume of 145 cm3. If block A has a greater mass than block B, what can be said of the relative densities of the two metals? (Assume that both blocks are solid.)
· Exercise 112 in Ch. 3 =
112. Classify each molecular picture as a pure substance or a mixture. If it is a pure substance, classify it as an element or a compound. If it is a mixture, classify it as homogeneous or heterogeneous.
(a)
(b)
(c)
(d)
