To determine the volume of water that should be added to obtain a one molar solution of HNO3, we need to consider both the concentration and the volume of the initial solution.
Let's break down the calculation into steps:
Step 1: Calculate the mass of HNO3 in the initial solution:
The specific gravity of HNO3 is given as 1.5 g/ml, which means that 1 ml of HNO3 weighs 1.5 grams. Therefore, the weight of 50 ml of HNO3 can be calculated by multiplying the volume (50 ml) by the specific gravity (1.5 g/ml):
Mass of HNO3 = Volume × Specific Gravity
Mass of HNO3 = 50 ml × 1.5 g/ml = 75 grams
Step 2: Calculate the mass of HNO3 in the desired one molar solution:
Since the concentration of the desired solution is given as 63.0% by weight, we can determine the mass of HNO3 required to make one molar solution by dividing the mass of HNO3 we calculated in Step 1 by the concentration:
Mass of HNO3 in desired solution = Mass of HNO3 / Concentration
Mass of HNO3 in desired solution = 75 grams / 0.63 = 119.05 grams
Step 3: Calculate the volume of the one molar solution:
To convert the mass of HNO3 in the desired solution to moles, we need to divide it by the molar mass of HNO3. The molar mass of HNO3 is 63.01 g/mol.
Number of moles of HNO3 = Mass of HNO3 / Molar Mass
Number of moles of HNO3 = 119.05 grams / 63.01 g/mol = 1.889 mol
Since the concentration of a one molar solution is 1 mol/L, the volume of the one molar solution can be obtained by dividing the number of moles of HNO3 by the molar concentration:
Volume of one molar solution = Number of moles of HNO3 / Molar Concentration
Volume of one molar solution = 1.889 mol / 1 mol/L = 1.889 L
Step 4: Calculate the volume of water to be added:
To get the volume of water required, we subtract the volume of the 50 ml initial solution from the volume of the one molar solution, as the water added will make up the rest of the volume:
Volume of water to be added = Volume of one molar solution - Volume of initial solution
Volume of water to be added = 1.889 L - 0.050 L = 1.839 L (or 1839 ml)
Therefore, to prepare a one molar solution of HNO3 from 50 ml of a solution with a specific gravity of 1.5 g/ml and 63.0% by weight, you need to add 1839 ml (or 1.839 L) of water.