Answer:
The answer to your question is molality = 0.34
Explanation:
Data
mass of NaBr = 14.57 g
mass of water = 415 g.
molality = ?
Process
1.- Calculate the molar mass of NaBr
NaBr = 23 + 80 = 103 g
2.- Calculate the moles of NaBr
103 g of NaBr ------------------ 1 mol
14.57 g of NaBr --------------- x
x = (14.57 x 1) / 103
x = 14.57 / 103
x = 0.141 moles
3.- Calculate the molality
molality = moles / volume
-Substitution
molality = 0.141 / .415
-Result
molality = 0.34
15c - 1.2m
1c - 1.2/15 = 0.08m
65c - 5.2m