Chem 222

Intro to Inorganic Chemistry

Problem Set 1 Answer Key

Summer 2011

Wednesday, May 11, 2011

1. Draw and label the 1s, 3s, 3p, and 3d orbitals, placing them correctly on cartesian axes (x,y,z).
1s and 3s:

3p: lobes can be signs/or shading z +

+

x

–

+
–

– y pz

px

py

3d: lobes can be signs/or shading z z

+

+

–

y

y

x
–
y

– x x
–

+ dyz z

y
+

–

–

x

+ dxz +

–

z

x

+

–

–

+ dxy y

+

– dz2 z

dx2–y2

2. (RC&O 2.20) Which atom should have the larger covalent radius, fluorine or chlorine? Give your reasoning.
Fluorine has electron configuration 1s22s22p5, while chlorine has electron configuration 1s22s22p53s23p5.
Chlorine should have a larger covalent radius because its “outermost” electrons are in the 3p orbitals, for which the radial distribution function extends much further out from the nucleus than do the 2p orbitals. “The larger the value of n, the larger the orbital”.
Note that this trumps the fact that the Zeff felt by the outermost electrons of Cl is higher than that experienced in F, as Zeff does not take into account the distance between the charges.
3. (a) (RC&O 1.5) Identify the orbital that has n = 5 and l = 1.
For the principle quantum number n = 5, the angular momentum quantum number, l, can have values
4,3,2,1,0. The number l=0 always corresponds to the s orbital; the l=1 always corresponds to the p orbitals. Thus, the above quantum numbers correspond to a 5p orbital.
(b) (RC&O 1.6) Idenitfy the orbital that has n = 6 and l = 0.
See explanation for 3(a): this is