Name _____________________________________________
Lab Station # ________________
Hydro-Carbon Lab
The ability of carbon to form four covalent bonds with other atoms makes possible a wide variety of organic molecules.
Organic molecules are found in both living and nonliving things. Organic molecules found in nonliving things are called
hydrocarbons. Hydrocarbons are the simplest organic compounds because they contain only carbon and hydrogen.
Because carbon atoms also bond easily to each other, there are numerous types of hydrocarbon molecules of varying
lengths and shapes.
Organic molecules found in living things are called macromolecules. Macromolecules—carbohydrates, lipids, proteins,
and nucleic acids—contain other atoms in addition to carbon and hydrogen and are large and complex. An organic
molecules shape depends on the arrangement of carbon atoms that make up the backbone of the molecule. Carbon
chains can form single, double, and triple bonds, and ring and loop shapes. The three-dimensional shape of the
molecule is critical in defining its properties and its function in living organisms.
In this activity, you will construct a variety of hydrocarbons and observe their features.
Procedure:
1. Methane, or natural gas, is a hydrocarbon that has a molecular formula of CH4. Using the molecular model kit,
construct a methane molecule and write its structural formula in the data table. Answer question 1
2. Construct another model of a methane molecule. Combine the two methane molecules to form ethane,
removing atoms if necessary. Write the molecular and structural formulas for ethane in data table 1. Answer
question 2.
3. Construct a third methane molecule. Add the methane molecule to the ethane molecule to form propane,
removing atoms if necessary. Write the molecular and structural formulas of propane in the data table. Answer
questions 3 and 4.
4. Ethene has a molecular formula of C2H4. Construct a model of ethene, then write its structural formula in the
data table. Answer question 5.
5. Construct another model of propane. Remove two atoms of hydrogen and attach the third carbon to one of the
other carbons to form propene. Write the molecular and structural formulas for propene in the data table.
Answer question 6.
6. Ethyne has a molecular formula of C2H2. Construct a model of ethyne, then write its structural formula in the
data table. Answer question 7.
7. Propyne has a molecular formula of C3H4. Construct a model of propyne and writs its structural formula in the
data table
8. Methane, ethane, and butane are alkanes- a group of hydrocarbons that have all single bonds. Ethene, and
propene are alkenes, or hydrocarbons that have a double bond. Ethyne and propyne are alkynes, of
hydrocarbons that have a triple bond. Construct two additional alkanes, two additional alkenes, and two
additional alkynes. Each should have either 5 or 6 carbons. Record the molecular and structural formulas for
each molecule in the data table.
1. Create each molecule. Fill in the molecular and structural formulas.
Hydrocarbon molecule
Molecular formula
Structural formula
Methane
CH4
Ethane
Propane
2. What do you notice about the number of bonds carbon can make?_________________________
3. What do you notice about the number of bonds between each carbon for the –ane molecule?________
4. Create each molecule. Fill in the molecular and structural formulas.
Hydrocarbon molecule
Molecular formula
Ethene
Structural formula
C2H4
Propene
5. What do you notice about how many bonds carbon makes?_____________________________
6. What do you notice about the number of bonds between each carbon for the –ene molecule?________
7. Create each molecule. Fill in the molecular and structural formulas.
Hydrocarbon molecule
Molecular formula
Ethyne
C2H2
Propyne
C3H4
Structural formula
8. What do you notice about how many bonds carbon makes?______________
9. What do you notice about the number of bonds between each carbon for the –yne molecule?________
Discussion Questions:
10. How many bonds are between –ane hydrocarbons?____________
11. How many bonds are between –ene hydrocarbons?____________
12. How many bonds are between –yne hydrocarbons?____________
13. Describe a trend relating the names of the hydrocarbons (-Ane, -Ene, -Yne) and the number of bonds between
the carbon atoms?
14. How many bonds did carbon always make? ________________
15. How many bonds did hydrogen always make?______________
16. What atoms had to be removed in order to join together the two methane molecules? __________________
17. In the ethane molecule, how many electrons are being shared (Hint: Each bond represents two shared
electrons) ?___________________
18. In the ethane molecule, what is the name of the type of bond is formed between the carbon
atoms?_____________________
19. What is the process called when you put together two molecules of methane to form ethane and water?
(HINT: methane + methane  ethane + water
Answer: ______________________________________
20. What do you need to add to ethane two break it into two methane molecules?
(HINT: ethane + ________  methane + methane)
Answer: ______________________________________
21. What is the name of the reaction in number 20 called?__________________________________
22. Draw three ways in which five carbon atoms could be joined to make different carbon skeletons.
a.
b.
c.