Answer: The molality of solution is 0.740 m.
Step-by-step explanation:
To calculate the mass of solvent (water), we use the equation:

Volume of water = 750 mL
Density of water = 1 g/mL
Putting values in above equation, we get:

To calculate the molality of solution, we use the equation:

Where,
 = Given mass of solute
 = Given mass of solute 
 = 100.0 g
 = 100.0 g
 = Molar mass of solute
 = Molar mass of solute 
 = 180 g/mol
 = 180 g/mol
 = Mass of solvent (water) = 750 g
 = Mass of solvent (water) = 750 g
Putting values in above equation, we get:

Hence, the molality of solution is 0.740 m.