Ch. 8 (e- config & trends)
The trends for IE, EA, and atomic radius/size
IE and EA increase up a group and to the right
atomic radius/size increases down a group and to the left
the difference between ionic and covalent bonds
ionic: cations and anions (metals and nonmetals); transfer of electrons
covalent: between nonmetals; sharing of electrons
what is steric number?
# of lone pairs + # of bonded atoms (on central atom)
number of valence electrons for Sb
5 (because in Group 15)
which is not isoelectronic with Cl-?
Ar, K+, S2-, Br-, Ca2+
Br-
Arrange the following in order of increasing ionization energy: Si, Ca, and Cl
Ca < Si < Cl
identify whether the following compounds have an ionic bond or covalent bond: COCl2, H2O, and Li2S
COCl2 and H2O are covalently bonded
Li2S has an ionic bond
4
draw the Lewis structure for ClO3-
3 single bonds and 1 lone pair on Cl; 6 e- on each O
Draw the Lewis structure for HCN. How many single, double, triple bonds are there (if any)? How many lone pairs are there (if any)?
1 single bond, 1 triple bond, and 1 lone pair
write the e- configuration for P3-. Which is bigger, P or P3-?
P3-: 1s22s22p63s23p6
P3- > P (gaining electrons)
determine which structure is the most stable (draw on board; slide 497)
see slide 497
BALPA of H2S
BALPA: tetrahedral
molecular shape: bent
the formal charge on N in the given compound:
see #11 for Lewis structure
[O - C - N]-
-2
C-O, Br-Br, Cl-F, P-Cl, Sn-F
most polar: Sn-F
least polar: Br-Br
Arrange the following species in order of increasing atomic radii: P, Rb, F, and Na
F < P < Na < Rb
Arrange the following in order of increasing lattice energy: NaCl, SrO, KCl, CaCl2
KCl < NaCl < CaCl2 < SrO
molecular shape of SBr4
seesaw
Give me an example of increasing IE and atomic radius. (each example must have at least 3 elements)
various answers
A certain central atom has 3 atoms and 1 lone pair bonded to it. Determine the BALPA and molecular shape.
BALPA: tetrahedral
molecular shape: trigonal pyramidal
ground state electron configuration for Ni2+ (can use short-hand notation)
[Ar] 3d8
Calculate an approximate enthalpy change for the following reaction:
CH4 + 2 O2 --> CO2 + 2 H2O
C—H => 413 kJ/mol
O = O => 498 kJ/mol
C = O => 805 kJ/mol
H—O => 464 kJ/mol
-114 kJ/mol
Find the steric number, BALPA, molecular shape, and bond angles in BrCl3
steric number: 5 --> BALPA: trigonal bipyramidal
molecular shape: t-shaped
bond angles: 90
what BALPA's are always associated with the steric numbers: 3, 4, 5, and 6
3: trigonal planar
4: tetrahedral
5: trigonal bipyramidal
6: octahedral
Write the electron configuration for S, Fe, and Sb, and circle the valence electrons. (use short hand notation for Fe and Sb)
S: 1s22s22p63s23p4
Fe: [Ar]4s23d6
Sb: [Ar]5s24d105p3