describe how you would prepare from the specified stock solution: 400 mL of 0.45 M urea starting with a 6 M urea stock solution
To prepare 400 mL of 0.45 M urea solution from a 6 M urea stock solution, you can follow the steps below:
1. Determine the volume of the stock solution required:
The formula to calculate the volume of a concentrated solution needed is:
V1 * C1 = V2 * C2,
where V1 is the volume of the stock solution, C1 is the concentration of the stock solution, V2 is the desired volume of the final diluted solution, and C2 is the desired concentration of the final diluted solution.
Plugging in the values, we have:
V1 * 6 M = 400 mL * 0.45 M
2. Solve the equation for V1:
V1 = (400 mL * 0.45 M) / 6 M
V1 = (180) / 6
V1 = 30 mL
3. Measure 30 mL of the 6 M urea stock solution using a graduated cylinder or pipette.
4. Pour the measured 30 mL of the 6 M urea stock solution into a larger container or beaker.
5. Add distilled water to make up the final volume of 400 mL. To do this:
a. Start with a container large enough to accommodate 400 mL of solution.
b. Carefully pour distilled water into the container while continuously monitoring the volume using a graduated cylinder or other measuring device.
c. Stop pouring when the total volume reaches 400 mL.
6. Mix the solution thoroughly by stirring or swirling gently until the urea is completely dissolved in the water.
After completing these steps, you will have prepared 400 mL of a 0.45 M urea solution from a 6 M urea stock solution. Make sure to label the container properly with the concentration and date for future reference.