How to Calculate Molality

How to Calculate Molality
So when 1 gm mole solute dissolved in 1 Kg solvent it’s called 1 molar or 1 M solution.
Symbol for Molarity is “m”

Molality = (weight of solute in gram) / (Molecular weight of solute × weight of solvent in Kg)

Means final weight of solution may be more than 1 Kg.
No matter of volume involve in this case.

Change in temperature will change the volume, so 
Molarity will change with temperature but Molality will remain constant with change in temperature, because it doesn’t have relation with volume.