All of the questions here are pertaining to the colligative properties of a solution and the preparation of solutions. Maybe, it would be best if you understand the equations to be used in order to answer these questions.<span>
Freezing point depression or Boiling point elevation:
</span><span>ΔT = -K (m) (i)
</span>ΔT is the change in the freezing point or the boiling point not the freezing point/boiling point. Therefore, it should be added to the original value of the property of the solvent.
<span>
K is a constant called the molal freezing point depression constant and for the boiling point is the boiling point elevation constant. It is a property of the solvent.
</span><span>
m is the concentration of the solute in the solvent in terms of molality or kg solute/kg solvent.
</span><span>
i is the vant hoff factor which will represent the number of ions which the solute dissociates when in solution.</span>
Answer:
Option b is correct.
Explanation:
When 
is dissolved in water, 
and 
are formed.
As is an weak base and is a strong acid, the resulting solution will be acidic in nature.
if K_b value is known, then pH of the solution can also be determined which will support prediction.
However, acidic and basic nature of the solution can be predicted without K_b value also.
So, among the given option, (b) is correct.
Answer:
At pH 8.59 the precipitation of acid will form.
Explanation:
The pH below which the drug will begin to precipitate can be calculated using the relation
pH = 
where S = total saturation solubility of the drug
S° = solubility of the undissociated species
substituting the respective values in equation, we get:
pH = 8.59
