Step-by-step explanation:
Freezing point depression:
It's colligative property and it describes that when we add a solute to a solvent the freezing point of the solution goes down. The formula that describes this property is:
ΔTf = i * Kf * m
Where ΔTf is the freezing point depression, i is the Van't Hoff factor, Kf is the constant and m is the molality of the solution.
Molality is expressed as the moles of solute divided by the mass of solvent in kg.
molality = moles of solute/kg of solvent
According to the problem we are dilluting the solution adding 100 g of water. That means that the molality of the solution will decrease (we are dividing by a greater number). And if we look at the formula of the freezing point depression we will see that if the molality decreases the freezing point depression decreases. So, the freezing point of the solution will increase.
Boiling point elevation:
When we add a solute to a solvent the boiling point of the solution will be elevated.
ΔTb = i * Kb * m
Where ΔTb is the boiling point elevation, i is the Van't Hoff factor, Kb is the constant and m is the molality of the solution.
If we are dilluting the solution adding 100 g of water, the molality of the solution will decrease. If the molality decreases the boiling point elevation decreases. So, the boiling point of the solution will decrease.
Answer: The freezing point goes up or increases. The boiling point goes down or decreases.