Calculation of Molality of the Solution

To calculate the molality of a solution, we need to know the moles of solute and the mass of the solvent. In this case, the solute is NaNO3 and the solvent is water.

Step 1: Calculate the moles of NaNO3
Given that the concentration of NaNO3 solution is 1M, we can determine the moles of NaNO3 using the formula:

Molarity (M) = Moles of solute / Volume of solution (L)

Rearranging the formula to solve for moles of solute:

Moles of solute = Molarity (M) * Volume of solution (L)

Since the volume of the solution is not given, we cannot directly calculate the moles of NaNO3. However, we can use the density of the solution to find the volume.

Step 2: Calculate the volume of the solution
The density of the solution is given as 1.25 g/mL. Since the density is the mass per unit volume, we can rearrange the formula to solve for volume:

Volume of solution (mL) = Mass of solution (g) / Density of solution (g/mL)

Assuming we have 1 L of the solution (1000 mL), we can calculate the mass of the solution as follows:

Mass of solution (g) = Volume of solution (mL) * Density of solution (g/mL)

Step 3: Calculate the moles of NaNO3
Now that we have the mass of the solution, we can substitute it into the formula to calculate the moles of NaNO3:

Moles of NaNO3 = Molarity (M) * Volume of solution (L)

Step 4: Calculate the molality of the solution
Finally, we can calculate the molality of the solution using the formula:

Molality (m) = Moles of solute / Mass of solvent (kg)

Since water is the solvent, we need to convert the mass of water from grams to kilograms:

Mass of solvent (kg) = Mass of solvent (g) / 1000

Step 5: Substitute the values and calculate the molality
Now we can substitute the values into the formula and calculate the molality:

Molality (m) = Moles of NaNO3 / Mass of water (kg)

Final Answer:

By following these steps and substituting the appropriate values, you can calculate the molality of the 1M NaNO3 solution.