Daily Post 13/4/12

The shapes of molecules are very important in their reactivity with the human body.  Post a 3D image of caffeine and cocaine and show how the shapes of these two molecules are quite similar.

Caffeine: C₈H₁₀N₄O₂

Cocaine: C₁₇H₂₁NO₄

Observation

From each chemical formula, each molecule uses the same type of atoms to create both molecules.

April 13

Daily Post 12/4/12

Energy content (density) of materials is a very important characteristic to meet our energy demands. Use thermodynamic concepts to rank the energy density of CNG (compressed natural gas), ethanol, gasoline and Li ion batteries.

                Material              MJ/Kg          MJ/L

1.       CNG                        53.6              9

2.       Gasoline                  47.2             34

3.       Ethanol                    30                24

4.       Li ion batteries          0.72             0.9-2.23

Source: http://en.wikipedia.org/wiki/Energy_density