Chem 113 Week 9 (Chapter 8)

Chem 113 – Week 9 (Chapter 8)

Not a whole lot of math today. Here’s the list of topics we should have down by the end of the week:

1. Electron configurations of ions:

Ex. Write ground state electron configurations for the following transition metal ions: a) Sc3+; b) Ti4+; c) V5+; d) Cr3+; e) Mn2+; f) Fe2+; g) Co2+; h) Fe3+; i) Ni2+; j) Cu+; k) Cu2+; l) Ag+; m) Au+; n) Au3+; o) Pt2+.

Ex. Write ground state electron configurations for the following ions: a) Li+; b) H-; c) N3-; d) F-; e) S2-; f) Al3+; g) Se2-; h) Br-; i) Rb+; j) Sr2+; k) Sn2+; l) Te2-; m) Ba2+; n) Pb2+; o) In3+; p) Tl+; q) Tl3+.

Ex. Group the species that are isoelectronic with each other:

C, Cl-, Mn2+, B-, Ar, Zn, Fe3+, Ge2+.

2. Screening and shielding of electrons:

3. Periodic Trends:

-Atomic Radius increases from right to left and from top to bottom

-Ionic Radius isn’t a general trend. Cations are generally smaller than their atoms and anions are generally larger than their atoms.

-Ionization Energy increases from bottom to top and from left to right.

-Electron Affinity increases from bottom to top and from left to right.

Ex. Arrange the following in order of increasing first ionization energy:

Na, Cl, Al, S and Cs.

Ex. Arrange the following atoms in order of decreasing atomic radius:

Na, Al, P, Cl, Mg

Ex. Explain which of the following cations is larger, and why:

Cu+ or Cu2+.

Ex. Arrange the elements in each of the following groups in order of the most positive electron affinity: a) Li, Na, K; b) F, Cl, Br, I

Ex. (Test 3 2003)Rank the following in order of increasing (left to right):

(a) atomic radii Mg, Sr, Rb

(b) ionic radii Mg2+, Na+, Al3+

(d) first ionization energy Ge, C, As

(e) electronegativity S, O, P

Ex. (Test 3 2004) The following questions relate to periodic trends.

a) Which has the larger atomic radius, Mg or Al

(b) Which has the smaller ionic radius, Fe2+ or Fe3+
(c) Which has the larger ionic radius, ClO41- or BrO41-

(d) Which has the larger 2nd Ionization Energy, Na or Mg
(e) Which has the smaller electronegativity, C or H
(f) Which element is more metallic, Ge or Sn

(e) Which has the greater electron affinity, Cl or F

Ex. (Test 3 2003) (i) Explain why the 1st ionization energy of Na is less than that of Li even though the nuclear charge has increased.

(ii) Explain why the ionization energy of O is less than that of N (both in the gas phase) even though the nuclear charge has increased.

4. Predicting Reaction Products:

Ex. (Final 2003) Complete and balance the following equations:

(a) ____ HNO3 (aq) + ____ NaOH (aq)

(b) ____ B (s) + ____ O2 (g) →

(d) ____Mg (s) + ____ N2 (g) →

(e) ____ Mg (s) + ____ CO2 (g) →

Ex. (Final 2004) Complete and balance the following reactions

(a) ___ Na2O(s) + ___ H2O(l) ®

(b) ___ SO3(s) + ___ H2O(l) ®

(d) ___ K(s) + ___ H2O(l) ®

(b) ___ Al(s) + ___ O2(g) ®

(e) ___ CaCO3(s) + heat ®

(f) ___ Si(s) + ___ F2 (g) ®

(g) ___ BaH2(s) + ___ H2O(l)®

Ex. (Test 3 2003) Complete and balance the following equations.

(a) ___ Mg (s) + ___H2O(l) →

(b) ___ Cs2O(s) + ___ H2O(l) →

(e) ___ CaC2(s) + ___ H2O(ll)

Ex. (Test 3 2004) Complete and balance the following reactions

(a) K2O(s) + H2O(l) ®
(d) CO2(g) + H2O(l) ®
(e) XeO3(s) + H2O(l) ®