You are provided with a 0.5M solution of NaCl. You require a working solution of 0.004M. Describe how you would prepare this working solution, including all steps and calculations. Hint: You want to use the least amount of reagents and consumables, serial dilutions.
To prepare a 0.004M solution from a 0.5M solution of NaCl using serial dilution, you will need the following materials:
1. A volumetric flask of suitable size for the final volume (e.g., 100 ml)
2. A pipette or measuring cylinder
3. Distilled water
4. A stirring rod or vortex mixer
Here are the steps to prepare the working solution:
1. Calculate the volume of the 0.5M solution needed to achieve the desired concentration. You can use the equation: C1V1 = C2V2, where C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume.
- C1 = 0.5M
- C2 = 0.004M
- V2 = 100 ml (assuming you want a final volume of 100 ml)
- V1 = (C2 * V2) / C1 = (0.004M * 100 ml) / 0.5M = 0.8 ml
Therefore, you will need to take 0.8 ml of the 0.5M NaCl solution for the dilution.
2. Measure 0.8 ml of the 0.5M NaCl solution using a pipette or measuring cylinder and transfer it to the empty volumetric flask.
3. Fill the volumetric flask to the mark with distilled water. Make sure the solution is thoroughly mixed by stirring with a stirring rod or using a vortex mixer.
4. Your 0.004M NaCl working solution is now ready for use.
Note: Take caution when handling chemicals, and always wear appropriate personal protective equipment while working in the laboratory.
To prepare a working solution of 0.004M NaCl from a 0.5M NaCl solution, you would need to use a process called serial dilution. This involves diluting the original solution multiple times to obtain the desired concentration.
Here are the steps you would take and the calculations involved:
1. Determine the volume of the 0.5M NaCl solution needed for the working solution. This can be calculated using the formula:
Volume (V) = (C2 * V2) / C1
Where C1 is the initial concentration (0.5M), C2 is the desired concentration (0.004M), and V2 is the desired volume of the working solution.
Let's assume you want to prepare 100 mL of the working solution (V2 = 100 mL).
V = (0.004M * 100 mL) / 0.5M
V ≈ 0.8 mL
So you would need 0.8 mL of the 0.5M NaCl solution.
2. Take a clean and dry container (such as a volumetric flask) and add the required amount (0.8 mL) of the 0.5M NaCl solution to it.
3. Now, add a suitable volume of a solvent, such as water, to make up the total desired volume of the working solution. In this case, you want to make 100 mL of the working solution.
4. Mix the contents thoroughly by swirling or inverting the container several times to ensure proper mixing.
By following these steps and calculations, you can prepare a working solution of 0.004M NaCl using serial dilution.