1. Which of the following is FALSE about alkanes? (Choose "f" if all are true.)
a. Alkanes contain ONLY hydrogen and carbon.
b. Carbon atoms in alkanes ALWAYS bond with four other atoms.
c. Hydrogen needs a total of 2 electrons to complete its outer shell.
d. Alkanes can be made of either straight chains or branched chains.
e. For two isomers of decane, an increase in branching leads to an increase in boiling point.
f. All of the above are true statements.
2. The bonds of carbon atoms in alkanes form
a. a cube with 90° angles between each bond.
b. a tetrahedron with 90° angles between each bond.
c. a cube with 109.5° angles between each bond.
d. a tetrahedron with 109.5° angles between each bond.
3. What is the general molecular formula for an alkane? ____________
4. Write the molecular formula for an alkane with 15 carbons. ____________
5. (3 points) Draw electron dot formula for a straight chain pentane.
6. (5 points) Draw the structural formula for TWO isomers of pentane.
7. (4 points) Fill in the blanks in the table of selected alkanes below:
NAME NUMBER OF CARBONS
Name
Number of Carbons
3
7
methane
nonane
8. Which of the following would be an example of EXTRAPOLATION?
a. Predicting next month's rainfall by looking at previous months' data on a graph
b. Finding the average mass of three beakers
c. Estimating the boiling point of a 5 carbon molecule, if given boiling points of 3, 4, 6, and 7 carbon molecules.
9. VERY CAREFULLY!!!! study the molecules below. How many different isomers are represented?___ (2 points)
10. (3 points) Name the alkane having a mass of 86 g/mol. You must show work to receive partial credit. (No, you may not use a calculator.) _____________
Some mostly useless information
MOLECULAR MODELS: ONLY ONE PERSON PER TABLE AT A TIME.
11. (2 points) Name and write the molecular formula for the molecule labeled A.
NAME:__________________
Molecular formula:_________
12. (2 points) Draw the structural formula for the molecule labeled B.
13. (3 points) Draw the structural formula of a DIFFERENT ISOMER with the same molecular formula as molecule B.
Teacher Notes:
Structure A is ethane. Structure B is hexane. Structures of these molecules need to be made available to students.
Questions? Comments??