if density of 5 m aqueous solution of naoh is 1.45 g ml then molality of the solution will be

To find the molality of the solution, we need to know the mass of the solute (NaOH) and the mass of the solvent (water).

Step 1: Calculate the mass of the solution The density of the solution is given as 1.45 g/ml. We have 5 m of the solution. So, the total mass of the solution is: Density * Volume = 1.45 g/ml * 5 m = 1.45 g/ml * 5000 ml = 7250 g

Step 2: Calculate the mass of the solvent (water) We know that a 5 m solution means that there are 5 moles of NaOH in 1 kg of water. The molar mass of NaOH is approximately 40 g/mole. So, the mass of NaOH in the solution is: 5 moles * 40 g/mole = 200 g The mass of the water in the solution is the total mass of the solution minus the mass of the NaOH: 7250 g - 200 g = 7050 g = 7.05 kg

Step 3: Calculate the molality of the solution Molality is defined as the number of moles of solute per kilogram of solvent. So, the molality of the solution is: 5 moles / 7.05 kg = 0.71 mol/kg

So, the molality of the 5 m aqueous solution of NaOH is approximately 0.71 mol/kg.