The simplest hydrocarbon , methane is a gas
with a chemical formula of CH4
[Ice
structure shown using the JMol Applet] | What
is the Geometry of Methane? Try this!! Click the
right mouse button with the cursor over the image--> Render --> Schemes
--> CPK Spacefill Click on the left mouse button and rotate the ice
structure. Do you see the open spaces in ice? They are formed at low temperatures
when water molecules form many stable hydrogen
bonds. Compare this structure to that below of water at room
temperature. | | |
Below is shown the
molecule Methane. Try
this. Notice
when you rotate the methane molecule it is off-center. Click on the tools pulldown
and select 'pickcenter'. Click the center carbon atom in the methane molecule.
Now rotate the methane molecule. It should rotate around the center carbon atom.
What polyhedral
stucture would you think methane best represents? Click on the tetrahedral box.
Now rotate the object to show how the molecule fits snugly within the tetrahedron.
| | To
rotate object hold left mouse button down and slide cursor arrow over object |
|
|
A principal
component of natural gas, methane is significant . Burning one molecule of methane
in the presence of oxygen releases one molecule of CO2[carbon dioxide) and two
molecules of H2O (water): CH4 + 2O2 ---> CO2 + 2H2O The strength of the carbon
hydrogen covalent bond in methane is among the strongest in all hydrocarbons,
and thus its use as a chemical feedstock is limited. The search for which one
can facilitate C-H bond activation in methane and other low alkanes is an area
of research with considerable industrial significance. Pure methane is odorless,
but when used as a fuel it is usually mixed with small quantities of strongly-smelling
sulfur compounds such as ethyl mercaptan to enable the detection of leaks. Methane
is a greenhouse gas with a global warming potential of 22 (meaning that it has
22 times the warming ability of carbon dioxide). Methane results from the decomposition
of certain organic matters in the absence of oxygen. It is therefore also classified
as a biogas.
1)
What is the distance of the hydrogen bond show?
Please
enter your answer in the space provided:
2) What is the measure of the HOH angle in a single molecule
of water?
3)What is distance between the oxygen
atoms in a water dimer?