[shichao]

1. Why does NCl3 have a larger dipole moment than NF3?

N-F bonds are more polar than N-Cl bonds, and they have the same trigonal pyramidal molecular geometry.

2. A 5.00 liter reaction vessel contains 25.0 grams of I2 vapor at 200 C. How many grams of I2 solid will form if the temperature is lowered to 100 C? The vapor pressure of I2 at 100 C is 45.5 torr. The molecular weight of I2 is 254 g/mol.

I know the answer to this question is about 22.5 grams, but how do you do the problem? I don't really know where to start.

3.Can you please tell me which of these compounds are paramagnetic and which of them are diamagnetic? Please explain how you can tell.

1. zinc chloride
2. copper(I) chloride
3.nickel(II) chloride
4. scandium chloride

I know nickel(II) chloride is the only paramagnetic compound, but how do you tell? Do you use molecular orbital theory?


Thanks in advance! 

[shichao]

I figured out the second one, but I still don't get the third one at all. Does anyone know how to do it?