Friday, January 7, 2011
Fri-Day 2
Physics - we reviewed the concept of "potential difference", measured in Volts. The potential difference between two points in an electric field is the amount of work done per Coulomb of charge moved between those two points; a Joule per Coulomb is a Volt, as is an electron-Volt per electron or per elementary charge.
We began a problem in which we deduced the net or resultant force on one charge from two other charges.
AP Chem - we manipulated the osmotic pressure formula into a more practical form to determine the molar mass of the dissolved solute that causes the osmotic pressure to increase.
We then saw how to compare a set of solutions of a given solvent, and arrange them in order of increasing or decreasing boiling or freezing point. Since k is the same for a given solvent, you just need to know how to assign the appropriate van 't Hoff factor based on whether the substance is a strong electrolyte (soluble salts and strong acids), weak electrolyte (weak acids), or non-electrolyte (ANY molecule, except an acid) and multiply "i" by the given molality.
We then looked at Raoult's Law, calculating the vapor pressure lowering effect of dissolving a non-volatile solute in a given solvent.
We began a problem in which we deduced the net or resultant force on one charge from two other charges.
AP Chem - we manipulated the osmotic pressure formula into a more practical form to determine the molar mass of the dissolved solute that causes the osmotic pressure to increase.
We then saw how to compare a set of solutions of a given solvent, and arrange them in order of increasing or decreasing boiling or freezing point. Since k is the same for a given solvent, you just need to know how to assign the appropriate van 't Hoff factor based on whether the substance is a strong electrolyte (soluble salts and strong acids), weak electrolyte (weak acids), or non-electrolyte (ANY molecule, except an acid) and multiply "i" by the given molality.
We then looked at Raoult's Law, calculating the vapor pressure lowering effect of dissolving a non-volatile solute in a given solvent.
# posted by C @ 10:29 PM 
