Calculation of Molality of Resulting Solution

To calculate the molality of the resulting solution, we need to follow the steps given below:

Step 1: Calculate the number of moles of urea in 1 kg of 2 molal urea solution.

Given, the molality of 2 molal urea solution is 2 mol/kg. Therefore, the number of moles of urea in 1 kg of solution is:

moles of urea = molality x mass of solvent
= 2 mol/kg x 1 kg
= 2 mol

Step 2: Calculate the number of moles of urea in 2 kg of 4 molal urea solution.

Given, the molality of 4 molal urea solution is 4 mol/kg. Therefore, the number of moles of urea in 2 kg of solution is:

moles of urea = molality x mass of solvent
= 4 mol/kg x 2 kg
= 8 mol

Step 3: Calculate the total number of moles of urea in the resulting solution.

The total number of moles of urea in the resulting solution is the sum of the moles of urea in the two solutions mixed together. Therefore,

Total moles of urea = moles of urea in 1 kg of 2 molal solution + moles of urea in 2 kg of 4 molal solution
= 2 mol + 8 mol
= 10 mol

Step 4: Calculate the mass of solvent in the resulting solution.

The mass of solvent in the resulting solution is the sum of the masses of solvent in the two solutions mixed together. Therefore,

Mass of solvent = Mass of solvent in 1 kg of 2 molal solution + Mass of solvent in 2 kg of 4 molal solution
= 1 kg + 2 kg
= 3 kg

Step 5: Calculate the molality of the resulting solution.

The molality of the resulting solution is given by the formula:

Molality = moles of solute / mass of solvent (in kg)

Substituting the values from Step 3 and Step 4, we get:

Molality = 10 mol / 3 kg
= 3.33 mol/kg or 3.33 m

Therefore, the molality of the resulting solution is 3.33 mol/kg or 3.33 m.

Ayush dost molality=moles of solute /mass of SOLVENT hota hai so in doing this (2+8)/3 aap log mass of solution se divide kar de rahe ho jo galat hai