Short Answer TypeArrange the following in the decreasing order of their basic strength in aqueous solutions:
CH3NH2, (CH3)2NH, (CH3)3 N and NH3
A 1.00 molar aqueous solution of trichloroacetic acid (CCl3COOH) is heated to its boiling point. The solution has the boiling point of 100.180C. Determine the van’t Hoff factor for trichloroacetic acid. (Kb for water = 0.512 kg mol-1)
Define the following terms:
(i) Mole fraction
(ii) Isotonic solutions
(iii) Van’t Hoff factor
(iv) Ideal solution
What do you understand by the ‘order of a reaction’? Identify the reaction order from each of the following units of reaction rate constant:
(i) L-1 mol-1
(ii) L mol-1 s-1
Name the two groups into which phenomenon of catalysis can be divided. Give an example of each group with the chemical equation involved.
What is meant by coagulation of a colloidal solution? Describe briefly any three methods by which coagulation of lyophobic sols can be carried out.
Coagulation is a process of aggregating together the colloidal particles so as to change them into large sized particles which ultimately settle as a precipitate. It can also be called as precipitation.
Coagulation is generally brought about by the addition of electrolyte.
When an electrolyte is added to the colloidal solution, the particles of the sol take up the ion which is oppositely charged and thus get neutralised.
Following are the three methods by which coagulation of lyophobic sols can be carried out.
(i) Electrophoresis: In this process, the colloidal particles move towards oppositely charged electrodes and get discharged resulting in coagulation.
(ii) Mixing of two oppositely charged sols: When equal proportions of oppositely charged sols are mixed, they neutralise each other resulting in coagulation.
(iii) Dialysis: By this method, electrolytes present in sol are removed completely and colloid becomes unstably resulting in coagulation.
Describe the principle involved in each of the following processes.
(i) Mond process for refining of Nickel.
(ii) Column chromatography for purification of rare elements.
is not likely to exist and why?
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