To find the molarity of the H3PO4 stock solution, we need to calculate the number of moles of H3PO4 present in 1 liter of the solution.
Assuming the assay percentage represents the mass percent of H3PO4 in the solution, we can calculate the mass of H3PO4 present in 1 liter of the solution:
Assay percentage = (mass of H3PO4 / mass of solution) * 100
Rearranging the formula, we get:
mass of H3PO4 = (assay percentage / 100) * mass of solution
Given that the density (specific gravity) of the solution is 1.24, we can calculate the mass of the solution:
mass of solution = volume of solution * density
Now we can substitute the values and calculate the mass of H3PO4:
mass of H3PO4 = (77.0 / 100) * (1 liter * 1.24 g/mL)
Next, we calculate the number of moles of H3PO4 using its molar mass:
molar mass of H3PO4 = 3 * (atomic mass of H) + atomic mass of P + 4 * (atomic mass of O)
Finally, we can calculate the molarity of the solution by dividing the moles of H3PO4 by the volume in liters:
Molarity = moles of H3PO4 / volume of solution
To prepare 1.00 L of a 2.00N solution, we need to adjust the volume of the stock solution. The molarity (M1) and volume (V1) of the stock solution, and the desired molarity (M2) and volume (V2) of the final solution are related by the equation:
M1 * V1 = M2 * V2
Substituting the given values, we can solve for V1:
(77.0 / 100) * V1 = 2.00 * 1.00
Now that we have the volume of the stock solution (V1), we can calculate the volume of the solvent (water) needed to prepare the desired solution:
Volume of water = V2 - V1
Substituting the values, we can determine the volume of water required to prepare the 2.00N solution.
Please note that to calculate the exact values, we would need the atomic masses and precise density of the solution. The calculations provided here are based on the given information and approximate values for demonstration purposes.
