describe how you prepare a 250cm3 of 0.5M solution Na2C03.indicate the various laboratory apparatus you will use

See your post above.

the procedure for use

To prepare a 250cm3 of 0.5M solution of Na2CO3 (sodium carbonate), you will need the following laboratory apparatus:

1. Beaker or Erlenmeyer flask: This will be used to hold and mix the solution.
2. Analytical balance: This is used to measure the exact mass of sodium carbonate required.
3. Measuring cylinder or pipette: This is used to measure the volume of water and sodium carbonate solution accurately.
4. Stirring rod: This will be used to mix the solution thoroughly.

Now, let's proceed with the steps to prepare the solution:

1. Calculate the amount of sodium carbonate needed: The molarity (M) of a solution is defined as the number of moles of the solute (in this case, Na2CO3) dissolved in one liter of the solution. To prepare 250cm3 (0.25 liters) of 0.5M Na2CO3 solution, we need to calculate the moles of Na2CO3 required. The formula to calculate moles is:

Moles = Molarity x Volume (in liters)

In this case, Moles = 0.5M x 0.25L = 0.125 moles

The molar mass of Na2CO3 is 105.99 g/mol. So, multiply the moles by the molar mass to get the mass of Na2CO3 required:

Mass = Moles x Molar Mass
= 0.125 moles x 105.99 g/mol = 13.25 grams

2. Weigh the calculated amount of sodium carbonate using an analytical balance and transfer it into the beaker or Erlenmeyer flask.

3. Add distilled water to the beaker or Erlenmeyer flask, maintaining a volume of 250cm3. You can use a measuring cylinder or pipette to measure the exact volume of water required.

4. Stir the mixture with a stirring rod until the sodium carbonate is completely dissolved.

5. Finally, transfer the solution into a clean and labeled container for further use or analysis.

Remember to wear the appropriate personal protective equipment (PPE), such as gloves and goggles, while handling chemicals in the laboratory.