Question

Describe how you would prepare 2.00 l of 0.250 m naoh from solid naoh

Answer 1

To prepare 2.00 L of 0.250 M NaOH, calculate the moles of NaOH required, convert to grams using its molar mass, dissolve the solid in less water than the final volume needed, then dilute to the final volume in a volumetric flask.

Step-by-step explanation:

To prepare 2.00 L of a 0.250 M NaOH solution from solid NaOH, you will need to perform the following steps:

1. Calculate the number of moles of NaOH required using the molarity formula:
   Moles of NaOH = Molarity (M) × Volume (L).
2. Convert the moles of NaOH to grams using the molar mass of NaOH.
3. Weigh out the calculated mass of solid NaOH.
4. Dissolve the solid NaOH in a volume of water that is less than the desired final volume (2.00 L).
5. Transfer the solution to a 2.00 L volumetric flask and add deionized water until the bottom of the meniscus is at the 2.00 L mark.
6. Mix the solution thoroughly to ensure homogeneity.

Example Calculation:

1. Number of moles of NaOH required = 0.250 mol/L × 2.00 L = 0.500 mol.

2. Mass of NaOH needed = 0.500 mol × 40.00 g/mol = 20.00 g of NaOH.

3. After weighing, dissolve the 20.00 g of NaOH in approximately 1.5 L of water, transfer to a 2.00 L volumetric flask, and add water to reach the 2.00 L mark.