- Deionized water

- Sodium phosphate dibasic heptahydrate (Na2HPO4·7H2O)

- Analytical balance

- Volumetric flask (1000 mL)

- Stirring rod or magnetic stirrer

Procedure:

1. Calculate the amount of sodium phosphate dibasic heptahydrate required. The molar mass of Na2HPO4·7H2O is 268.07 g/mol. To prepare 0.01 M sodium phosphate, you will need:

```

0.01 mol/L * 1 L * 268.07 g/mol = 2.6807 g Na2HPO4·7H2O

```

2. Weigh out 2.6807 g of sodium phosphate dibasic heptahydrate using an analytical balance.

3. Transfer the sodium phosphate dibasic heptahydrate to a 1000 mL volumetric flask.

4. Add deionized water to the flask until it is about half full.

5. Stir the solution using a stirring rod or magnetic stirrer until the sodium phosphate dibasic heptahydrate is completely dissolved.

6. Add more deionized water to the flask until the volume reaches the 1000 mL mark.

7. Mix the solution thoroughly to ensure that it is homogeneous.

Your 0.01 M sodium phosphate solution is now ready to use.