Answer:
(a) 0.575 m;
(b) 0.527 m
Explanation:
Let's use the freezing point depression law in each of these cases.
(a) According to the law:
Rearrange the equation for molality, b:
NaCl is an ionic substance, 1 mole of it dissociates into 2 moles of ions, sodium ion and chloride ion, this means the van 't Hoff factor i = 2.
Here:
is the initial freezing point of water,
is the final freezing point of water.
For water:
Applying the equation
(b) Applying the same equation for the same salt and the same conditions, except a new freezing point, we would expect to obtain: