Tuesday, October 03, 2006
Tuesday Recap
AP: applied Dalton's Law to two "collection of gas over water" stoichiometry problems; good point that all gases in a mixture occupy the ENTIRE volume of the container so you just have to use a single value for V for all gases in any given calculation.
We began our first of many descriptive chemistry sets...make sure that you re-write those and try to GENERALIZE each reaction so that you recognize them when the elements are slightly change i.e. using Cl2 instead of Br2 in a single replacement of iodide ion.
We began one more partial pressure problem. Tomorrow, we do the amazing Cannizzaro Method for determining the atomic mass of an unknown in several compounds and then we'll try to finish the unit.
D,G Honors: we did atoms --> moles --> mass problems and the reverse mass-->moles--> atoms problems....these are ALWAYS two part problems; you CANNOT convert a number of atoms of an element to a mass (in grams) in one step and you CANNOT in ONE step convert a specific mass of a certain element to a specific number of atoms. Both calculation require you to calculate the number of MOLES of atoms of a substance. Once you know the number of MOLES of a substance, then you can easily convert the number of moles to the number of atoms or to the number of grams by using the appropriate ratio or conversion factor.
E: we finished up Dalton's Laws with the Law of Multiple Proportions. Make sure that you are READY for your second test of the semester, which is on THURSDAY. The test will be worth 100 points towards your quarterly average.
We began our first of many descriptive chemistry sets...make sure that you re-write those and try to GENERALIZE each reaction so that you recognize them when the elements are slightly change i.e. using Cl2 instead of Br2 in a single replacement of iodide ion.
We began one more partial pressure problem. Tomorrow, we do the amazing Cannizzaro Method for determining the atomic mass of an unknown in several compounds and then we'll try to finish the unit.
D,G Honors: we did atoms --> moles --> mass problems and the reverse mass-->moles--> atoms problems....these are ALWAYS two part problems; you CANNOT convert a number of atoms of an element to a mass (in grams) in one step and you CANNOT in ONE step convert a specific mass of a certain element to a specific number of atoms. Both calculation require you to calculate the number of MOLES of atoms of a substance. Once you know the number of MOLES of a substance, then you can easily convert the number of moles to the number of atoms or to the number of grams by using the appropriate ratio or conversion factor.
E: we finished up Dalton's Laws with the Law of Multiple Proportions. Make sure that you are READY for your second test of the semester, which is on THURSDAY. The test will be worth 100 points towards your quarterly average.
# posted by C @ 10:25 AM 
