Which of the following ionic compounds has the highest melting point?
Help: Lattice energy
Select one:
a. Cs2O
b. K2O
c. BeO
d. SrO
e. LiF
f. CsI
2 answers
Lattice energy generally decreases as we go down the periodic table and with charge. So mark off all of the group I oxides since they have +1 charge and that leaves just two from which to choose; i.e., SrO and BeO. BeO is more covalent bond whereas SrO is ionic. I think I would choose BeO as the higher melting point of the two; however, if you look them up on the web the mp of BeO is listed as 2507 C while that of SrO is 2531 C. Close but SrO is higher.
Which of the following ionic lattices would have the highest melting point?
A. Potassium oxide
B. Beryllium oxide
C. Boron nitride
D. Lithium chloride
A. Potassium oxide
B. Beryllium oxide
C. Boron nitride
D. Lithium chloride