Silberberg/Chemistry: The Molecular Nature of Matter and Change

Online Learning Center Demo (Student) - ChemQuest Questions

Chapter 1

1. Of the three temperature scales used today, the Kelvin scale is the one most often used in chemistry problems. The website at http://www.math.csusb.edu/history/public_html/Mathematicians/Thomson.html gives a brief overview of the life of William Thomson (aka Lord Kelvin). Read through his history and answer the following:

(a) What was Kelvin's absolute scale based on, and when was it introduced?
(b) The absolute temperature scale derives its name from Thomson's title. What was his full title (in 1892)?
(c) In what year was he knighted, and for what specific work was this honor bestowed upon him?
Now, go to http://www.eb.com/cgi-bin/g?keywords=Absolute+Zero&hits=10.
(d) Find the definition of absolute zero, and write down the corresponding Celsius and Fahrenheit temperatures.

2. Of the many periodic charts on the World Wide Web, Web Elements at http://www.shef.ac.uk/~chem/web-elements/, has become one of the most popular sites to access information about the elements. It has become a favorite among many chemistry students and may become one of your favorites after you visit the site and answer the following questions:

Click on the box that contains the number eleven and the symbol Na .

(a) What is the name of this element?
Now, go to the General Index.
(b) What is the density of this element in its liquid state?
(c) What is the volume occupied by 50.0 g of this element?

3. The website, "Nitrogen: Food or Flames", at http://www.cems.umn.edu/~aiche_ug/history/h_s_n2.html presents a lot of information about the element nitrogen and some of the common compounds it forms.

(a) Name three compounds from this site that contain nitrogen, and tell what each compound is responsible for in our every day lives.
(b) Plants play two very important roles in the nitrogen cycle. What are they?
(c) Give the name of a compound containing nitrogen that is used as the explosive charge in shells and bombs.

4. Specific Gravity is the ratio of the mass of a substance to the mass of an equal volume of distilled water at 4°C. It is a unitless quantity. Since the mass of one mL of water at 4°C is exactly 1 g, the specific gravity (unitless) is numerically equivalent to its density (in grams per mL).

Now, go to http://chemfinder.camsoft.com/. Type in carbon tetrachloride as the name of the compound to be found and submit your query.

(a) Convert the melting point given to degrees Fahrenheit.
(b) Convert the boiling point given to degrees Kelvin.
(c) A sample of carbon tetrachloride weighs 15 g. What volume does it occupy at -22.9°C?

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