Tasks and exercises
1.
Calculate the degree of ionization of 0.1 m acetic acid providing
that its freezing point is -0.188°C.
2.
What’s the osmotic pressure of a 2.0 m solution of sodium chloride at
20°C?
3.
Calculate the “degree of dissociation” of 0.01 m solution of ammonium
chloride providing that its freezing point depression is
0.0367°C.
4.
A 50.00 g sample of a solution of naphthalene
[C10H8(s)] in benzene [C6H6 (l)] has
a freezing point of 4.45°C. Calculate the mass percent
C10H8 and the boiling point of this solution.
5.
Predict the approximate freezing points of 0.10 m solutions of
the following solutes dissolved in water: (a)
CO(NH2)2 (urea); (b) NH4NO3;
(c) HCl; (d) CaCl2 ; (e) MgSO4 ; (f) C2H5OH
(ethanol); (g)
HC2H3O2 (acetic acid).
6.
Calculate the van t Hoff factors of the following weak electrolyte
solutions: 0.050 m HCHO2, which begins to freeze at
-0.0986°C.
7.
An isotonic solution is described as 0.92% NaCl (mass/volume). Would
this also be the required concentration for isotonic solutions of other salts,
such as KCl, MgCl2, or MgSO4? Explain.
8.
Calculate the van t Hoff factors of the following weak electrolyte
solutions: 0.100 M HNO2, which has a hydrogen ion (and nitrite
ion) concentration of 6.91 × 10-3 M.
9.
What mass of each product is produced in each of the electrolytic
cells of the previous problem if a total charge of 3.33 × 105ºC passes through each cell? Assume the voltage is sufficient to
perform the reduction.
10. The dissociation constant of NH4OH at 298 K is 1.8 ×
10-5. Calculate the degree of dissociation of 0.01 M Sol. of
NH4Cl. Kw at 298 K =
10-14