describe how you would prepare 500.0 ml of 0.400M NaCl solution, starting from solid NaCl
To prepare a 500.0 ml of 0.400M NaCl solution starting from solid NaCl, you will need to follow several steps. Here's a step-by-step guide:
1. Determine the mass of NaCl needed:
- Calculate the moles of NaCl required using the equation: moles = molarity * volume (in liters)
- moles = 0.400M * 0.500L (convert 500.0 ml to liters)
- moles = 0.200 mol
2. Calculate the mass of NaCl required:
- Use the molar mass of NaCl, which is approximately 58.44 g/mol.
- mass = moles * molar mass
- mass = 0.200 mol * 58.44 g/mol
- mass = 11.688 g (rounded to three decimal places)
3. Weigh the required amount of solid NaCl:
- Use a balance or scale to accurately weigh out 11.688 grams of NaCl.
4. Dissolve NaCl in a container:
- Pour the weighed NaCl into a clean, dry container.
- Add a small volume of deionized water (e.g., 100-200 ml) to dissolve the NaCl more easily.
5. Add more deionized water to reach the final volume:
- Slowly add deionized water to the container, while stirring to ensure complete dissolution.
- Continue adding water until the volume reaches the desired final volume of 500.0 ml.
6. Mix thoroughly:
- Use a glass rod or stir bar to mix the solution thoroughly.
- Make sure there are no visible solid NaCl particles remaining.
7. Check the final volume and adjust if necessary:
- Use a graduated cylinder or volumetric flask to measure the final volume accurately.
- Add more deionized water if the volume is below 500.0 ml, or remove excess solution if the volume is above 500.0 ml.
8. Label and store:
- Label the container with the concentration, solute, and any other relevant information.
- Store the NaCl solution in a tightly sealed container to prevent evaporation or contamination.
Remember to wear appropriate protective gear (lab coat, gloves, etc.) and work in a well-ventilated area when handling chemicals.
To prepare a 500.0 ml of 0.400M NaCl solution from solid NaCl, you would need to follow these steps:
1. Determine the amount of NaCl needed:
The formula for molarity (M) is: M = moles/volume.
Rearranging the formula, we get moles = M x volume.
Substitute the values: moles = 0.400 M x 0.500 L = 0.200 moles.
2. Calculate the amount of NaCl in grams:
Use the molecular weight of NaCl, which is 58.44 grams/mole.
Mass = moles x molecular weight = 0.200 moles x 58.44 g/mole ≈ 11.69 grams.
3. Weigh out the desired amount of solid NaCl:
Using a balance, measure out approximately 11.69 grams of solid NaCl.
4. Transfer the NaCl to a clean and dry container:
Once measured, pour the solid NaCl into a container that can hold at least 500.0 ml of solution. Make sure the container is clean to prevent any contamination.
5. Add distilled water and dissolve the NaCl:
Slowly add distilled water to the container, while stirring gently to aid in the dissolution of NaCl. Continue adding water until the combined volume (NaCl + water) reaches 500.0 ml. Stir until all the solid NaCl has completely dissolved.
6. Verify the final volume:
After complete dissolution, use a measuring cylinder or graduated cylinder to measure the final volume of the NaCl solution. Adjust if necessary to ensure it is precisely 500.0 ml.
7. Label and store:
Label the container with the details of the solution, including the concentration (0.400 M) and contents (NaCl). Store the solution in a labeled container in a suitable location.
Please note that when handling chemicals, it is essential to wear appropriate personal protective equipment and follow safety protocols.
How many mols do you want? That's M x L = ?mols.
Then mol = grams/molar mass.
I think the point of this question is how to physically describe how it is prepared. Weigh that many grams NaCl, add to a 500 mL volumetric flask, add some water, swirl until all of the NaCl is dissolved, thn add water to the mark of the volumetric flask.