How to prepare a 500ml 0.2M NaOH solution from 2.0M NaOH solution
you want 1/10 the concentration, so you will need 10 times the volume.
I think the question here hinges on HOW to prepare. There are two steps.
1. Determine how much of the 2.0 M NaOH to use. I use
c1v1 = c2v2 where
c = concn
v = volume
2.0*v1 = 0.1*500
v1 = 50 mL of the 2.0M solution.
Step 2. Here is where many students miss it. They will answer, "Mix 50 mL of the 2.0M NaOH and add 495 mL H2O to make a total of 500 mL." But that assumes the volumes are additive. The correct answer is
"Pipet 50. mL of the 2.0 M NaOH into a 500 mL volumetric flask, add water to the mark on the volumetric flask and mix thoroughly." Note that you may have added "very close" to 495 mL H2O but not that exact amount.
To prepare a 500 mL 0.2 M NaOH solution from a 2.0 M NaOH solution, you will need to dilute the concentrated solution with water. Here's a step-by-step guide:
Step 1: Calculate the volume of concentrated solution needed.
To calculate the volume of 2.0 M NaOH solution required, use the formula:
Volume of concentrated solution = (M2 x V2) / M1
Where:
M1 = initial concentration of the concentrated solution (2.0 M)
V2 = final volume of the desired solution (500 mL)
M2 = final concentration of the desired solution (0.2 M)
Volume of concentrated solution = (0.2 M x 500 mL) / 2.0 M
= 100 mL
Step 2: Measure 100 mL of the 2.0 M NaOH solution.
Use a graduated cylinder or a pipette to measure 100 mL of the 2.0 M NaOH solution. Pour it into a clean and labeled container.
Step 3: Add water to reach the desired final volume.
After adding the measured 100 mL of the 2.0 M NaOH solution, add water to the container while stirring to reach the final volume of 500 mL. Ensure that the solution is well-mixed.
Step 4: Label and store the solution.
Label the container with the concentration and contents of the solution (0.2 M NaOH solution) and the date of preparation. Store the solution in a properly labeled and secure container, away from direct sunlight.
Now you have successfully prepared a 500 mL 0.2 M NaOH solution from a 2.0 M NaOH solution.
To prepare a 500ml 0.2M NaOH solution from a 2.0M NaOH solution, you can use the formula:
C1V1 = C2V2
Where:
C1 = initial concentration of the NaOH solution (2.0M)
V1 = initial volume of the NaOH solution (unknown)
C2 = final concentration of the NaOH solution (0.2M)
V2 = final volume of the NaOH solution (500ml)
Let's solve for V1.
Substituting the known values into the formula:
(2.0M) * V1 = (0.2M) * (500ml)
Now, rearrange the equation and solve for V1:
V1 = (0.2M) * (500ml) / (2.0M)
V1 = 100ml
Therefore, you need to take 100ml of the 2.0M NaOH solution and dilute it with water to a final volume of 500ml to obtain a 0.2M NaOH solution.