Answer:
The answer to your question is m = 1.6
Step-by-step explanation:
Data
mass of NaCl = 111 g
volume of water = 1.2 L
Molality = ?
Formula
Molality = number of moles / volume (L)
Process
1.- Calculate the moles of NaCl
Molecular mass = 23 + 35.5 = 58.5 g
1 mol of ------------------- 58.5 g
x -------------------- 111 g
x = (111 x 1) / 58.5
x = 1.897 moles of NaCl
2.- Calculate the mass of water
density of water = 997 kg/m³
mass = volume x density
mass = 0.0012 x 997
mass = 1.19 kg
3.- Calculate molality
m = 1.897/1.19
m = 1.6