A student must prepare 2.00 L of 0.100 M Na2CO3 (106 g/mol) Which is the best procedure for preparing this solution ?
If you can buy Na2CO3 that you KNOW is pure, weigh 21.2g (0.2 mol), place in a 2L volumetric flask, add some water, swirl until all is dissolved, then add water to the mark of the volumetric flask. If you can't find what you KNOW is good Na2CO3, you prepare your own by heating NaHCO3 to 275 C until you have constant weight (abot 2-3 hours).
To prepare 2.00 L of 0.100 M Na2CO3 solution, you will need to follow these steps:
Step 1: Calculate the amount of Na2CO3 needed
To determine the amount of Na2CO3 needed, you can use the formula:
Amount (mol) = concentration (M) × volume (L)
Given:
Concentration (M) = 0.100 M
Volume (L) = 2.00 L
Amount (mol) = 0.100 M × 2.00 L = 0.200 mol Na2CO3
Step 2: Convert the amount of Na2CO3 to grams
To convert the amount of Na2CO3 from moles to grams, you need to know the molar mass of Na2CO3, which is 106 g/mol.
Mass (g) = Amount (mol) × Molar mass (g/mol)
Mass (g) = 0.200 mol × 106 g/mol = 21.2 g Na2CO3
Step 3: Dissolve the Na2CO3 in a suitable amount of water
To dissolve the Na2CO3, you will need to use a suitable amount of water. Since you want to prepare a 2.00 L solution, it is recommended to start with a smaller amount of water to dissolve the solid, and then add more water to reach the final volume.
Start by adding about 1/3 to 1/2 of the final volume (2.00 L) of water to a clean container. In this case, you can use approximately 1.00 L of water to dissolve the Na2CO3.
Step 4: Add the Na2CO3 to the water and stir
Gradually add the 21.2 g of Na2CO3 to the container with the water while stirring continuously. Ensure that the Na2CO3 completely dissolves in the water.
Step 5: Add more water to reach the final volume
Once the Na2CO3 has fully dissolved, add more water to the container until the final volume of the solution reaches 2.00 L. Stir the solution to ensure uniform concentration.
Step 6: Transfer the solution to a storage container
After preparing the solution, transfer it to a storage container, such as a clean and labeled bottle. Make sure to seal the container tightly to prevent any contamination.
Now, you have successfully prepared 2.00 L of 0.100 M Na2CO3 solution.
The best procedure for preparing a 2.00 L solution of 0.100 M Na2CO3 would involve calculating the amount of Na2CO3 needed and then diluting it to the desired volume. Here's how you can do it:
Step 1: Calculate the amount of Na2CO3 needed.
The formula for molarity (M) is M = moles of solute / liters of solution.
In this case, you want a 0.100 M solution and a volume of 2.00 L. So, the moles of Na2CO3 needed can be calculated as:
moles of Na2CO3 = Molarity x Volume
moles of Na2CO3 = 0.100 mol/L x 2.00 L = 0.200 moles
Step 2: Convert moles to grams.
To convert moles to grams, you need to know the molar mass of Na2CO3, which is given as 106 g/mol. Multiply the moles of Na2CO3 by its molar mass to get the mass required:
mass of Na2CO3 = moles of Na2CO3 x molar mass of Na2CO3
mass of Na2CO3 = 0.200 mol x 106 g/mol = 21.2 grams
Step 3: Dissolve and dilute the Na2CO3.
Weigh out 21.2 grams of Na2CO3 and dissolve it in a smaller volume of water, ensuring that all the solid has completely dissolved. Once the solid is dissolved, transfer the solution to a larger container, such as a volumetric flask, and then add enough water to reach the final volume of 2.00 L. Make sure to mix well to ensure uniformity.
By following this procedure, you can prepare a 2.00 L solution of 0.100 M Na2CO3.