12. How do you make 500ml of a 4N Na3PO4
To make 500ml of a 4N Na3PO4 solution, you would need to know the molar mass of sodium phosphate (Na3PO4). The formula for sodium phosphate is Na3PO4, which means for every 1 molecule of Na3PO4, you have 3 atoms of sodium (Na), 1 atom of phosphorus (P), and 4 atoms of oxygen (O).
Step 1: Calculate the molar mass of Na3PO4:
The atomic masses of the elements are:
- Sodium (Na) = 22.99 g/mol
- Phosphorus (P) = 30.97 g/mol
- Oxygen (O) = 16.00 g/mol
The molar mass of Na3PO4 can be calculated as follows:
(3 * Na) + P + (4 * O) = (3 * 22.99) + 30.97 + (4 * 16.00) = 163.94 g/mol
Step 2: Determine the number of moles needed:
To make a 4N solution, 4 moles of Na3PO4 are needed per liter (1000ml) of solution.
Given that we want to make 500ml of solution, we need to determine the number of moles needed for this volume.
Using the formula:
moles = (N * volume) / 1000
moles = (4 * 500) / 1000 = 2 moles
Step 3: Calculate the mass of Na3PO4 needed:
The mass of Na3PO4 can be calculated using the molar mass and the number of moles required.
mass = moles * molar mass
mass = 2 * 163.94 = 327.88 grams
So, to make 500ml of a 4N Na3PO4 solution, you will need 327.88 grams of Na3PO4.