I am not sure how to solve this, because they should give you the volume of the solvent. Otherwise, we don't know the molality and cannot calculate the Tb...

The Kb is 1.78 for 1 kilogram of aceton. What is the value of Delta Tb for 100 grams of acetone?

My calculation as follows:
Tb = Kb x mass x i Since aceton is non electrolytes, so i = 1, so TB = Kb x mass
100 g x (1.78 / 1000g ) so 0.178, but solution said 1.78 so I posted it here

The Kb is 1.78 for 1 kilogram of aceton. What is the value of Delta Tb for 100 grams of acetone?

My calculation as follows:
Tb = Kb x mass x i Since aceton is non electrolytes, so i = 1, so TB = Kb x mass
100 g x (1.78 / 1000g ) so 0.178, but solution said 1.78 so I posted it here