Tuesday, May 15, 2012

a. Solid K has an electron configuration of [Ar]4s1, so it has an unpaired electron. This allows electric current to flow through the structure. KNO3 does not have an unpaired electron, so no electricity flow in.
b. SbCl3 has measurable dipole movement because the molecule is polar, so there is attraction between SbCl3 and other polar molecules. SbCl5 is non-polar, so there is no dipole interaction occurring.
isn't chemistry fun!
c. Both of these molecules are non-polar, but CBr4 has the higher boiling point because it has more electrons, and therefore it is harder to separate.
d. NaI is polar, so it is easy for it to bond with other molecules in a solution. I2 is non-polar and symmetrical, so it is harder to separate.
f. Sulfur has an expanded octet (12 electrons) because it is in the third energy level, so there are more options for bonding. Oxygen is only in the second energy level, and therefore is restricted to 8 electrons.


  1. Nice answers Cara! While I agree with most of the things you have said, I would like to add a bit too. On A, I think that a large part of the answer is that K is a metal and KNO3 is a solid ionic compound. This alone makes it obvious that K can conduct electricity and KNO3 cannot. Also on B, SbCl3 has a measurable dipole moment, not movement. Good job anyways!

  2. I'm not sure if moment is the right wording for it and movement does get the picture across, so does the actual picture.

  3. Great explanations!! I would have like to see a more detailed description on some of them, such as the ones that Brant brought up. An example is c. You said that it was non polar, but you didn’t mention any other intermolecular forces that could be acting on it, such as London-Dispersion Forces where the bigger atoms have more electrons and there more has more ‘allowance’ to shift. The same thing with d and the different intermolecular forces.