UNIVERSITY OF DAR ES SALAAM
CHEMISTRY DEPARTMENT
CH 219 TUTORIAL 2
1.
Distinguish between a disproportionation reaction and a redox reaction.
2.
Write a general balanced chemical equation to illustrate the thermal decomposition
of the peroxides of the Group 1 (IA) metals.
3.
Explain why potassium peroxide is thermally much less stable than caesium
peroxide.
4.
Consider the lithium halides, lithium fluoride and lithium bromide. Which one is
more soluble in water? Explain your answer.
5.
The charge density of Li+ differs from those of the other Group 1 (IA) metals. Give
three examples in which Lithium behaves differently as a result of the differing charge
density.
6.
Explain why Group 2 (IIA) metals form M2+ cations rather than M+ cations although
the ionization energy required to form M2+ cations is much larger than that required
to form M+ cations.
7.
Explain the observation that although Mg and Sr are both in Group 2, the melting
point of MgO is much higher than that of SrO.
8.
Briefly describe the use of limestone in the manufacture of paper.
9.
The metal radius of sodium (1.86 Å) is lower than that of rubidium (2.48 Å) whereas
its hydrated ionic radius (2.76 Å) is larger than that of the hydrated ionic radius of
rubidium (2.28 Å). Explain.
10.
Distinguish between Lattice energy and Ionization energy.
11.
Explain why the halogens have the most negative electron affinities whereas all the
noble gases have positive values of electron affinities.