Given information
- The of the buffer solution is .
- The freezing point is .
- The density of the solution is .
Step-by-step explanation
The Henderson-Hasselbalch equation is used to compute the concentrations of benzoic acid and sodium benzoate as follows:
The acid is benzoic acid, and the base is sodium benzoate in the specified buffer system. As a result, the above equation above becomes,
The value of for benzoic acid is .
Substitute the respective values of the given and for the system in the above expression:
Let the concentration of benzoic acid be . Therefore, the above equation becomes,
The molality of the solution is calculated by the formula,
Where,
is freezing point depression.
is molality.
is molal freezing point depression constant ( ).
The freezing point of pure solvent water is .
The value of
Substitute the value of and in the above equation.
It means that total moles to of solvent.