Tuesday, December 8, 2009
Tues-Day 1
Bio 3/6- we discussed the experimental setup that shows how aerobically respiring heterotrophs produce CO2, which increases the acidity/lowers the pH of the solution they are in, thus turning the BTB indicator from blue to yellow. (Some CO2 reacts with the water to produce carbonic acid).
However, when a photosynthetic autotroph (plant or algae) is added to the setup in the presence of light energy, the plant will consume/absorb the CO2 in the solution and perform photosynthesis, thus releasing oxygen that can be used by both the heterotroph and the plant for aerobic respiration! Because the CO2 gets removed from the solution, the BTB color turns blue due to the decrease in acidity.
AP Chem - we finished our overview of intermolecular attractions, noting the relative strength of each and the proper terms for each. Ion-dipole attractions are experienced between the ions of ionic compounds and polar solvent molecules by which the partially charged region of a polar molecule is attracted to the oppositely charged ion of the salt.
We then got into the ALL-IMPORTANT skill of PROPERLY and METHODICALLY writing/drawing the correct Lewis structure of a given molecule or ion. This is crucial to understanding the geometry of the molecule or ion and the relative polarity of the molecule.
# posted by C @ 2:24 PM 
