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.
Unlock all Textbook Solutions
