A student needed to make 200 ml of 0.1 M naOH. If the stock soluton was 0.75 M, how much of the stock solution and how much wter would be needed to make this solution?

mL1 x M1 = mL2 x M2

200 x 0.1 = mL2 x 0.75 so you need 26.7 mL of the stock solution and enough water to make 200 mL of solution. Watch the number of significant figures.

To determine how much of the stock solution and water would be needed to make 200 ml of 0.1 M NaOH, we can use the formula:

C1V1 = C2V2

where C represents concentration and V represents volume.

Given:
C1 (concentration of stock solution) = 0.75 M
V1 (volume of stock solution) = ?
C2 (desired concentration) = 0.1 M
V2 (desired volume) = 200 ml

We need to find V1, the volume of the stock solution.

Using the formula:

C1V1 = C2V2

0.75 M * V1 = 0.1 M * 200 ml

Now, let's solve for V1:

V1 = (0.1 M * 200 ml) / 0.75 M

V1 = 20 ml / 0.75

V1 ≈ 26.67 ml

Therefore, you would need approximately 26.67 ml of the 0.75 M NaOH stock solution.

To determine the amount of water needed, we can subtract the volume of the stock solution from the desired volume:

Volume of water = V2 - V1

Volume of water = 200 ml - 26.67 ml

Volume of water ≈ 173.33 ml

Therefore, you would need approximately 173.33 ml of water to make the 0.1 M NaOH solution.

To solve this problem, we need to use the equation for the dilution of a solution:

C1V1 = C2V2

Where:
C1 = concentration of the stock solution
V1 = volume of the stock solution
C2 = desired concentration of the final solution
V2 = desired volume of the final solution

In this case:
C1 = 0.75 M (concentration of the stock solution)
V1 = volume of the stock solution (to be determined)
C2 = 0.1 M (desired concentration of the final solution)
V2 = 200 ml (desired volume of the final solution)

First, let's rearrange the equation to find V1:

V1 = (C2 * V2) / C1

V1 = (0.1 M * 200 ml) / 0.75 M

V1 = (20 ml) / 0.75

V1 = 26.67 ml (rounded to two decimal places)

So, you would need to measure 26.67 ml of the stock solution (0.75 M NaOH) and then add enough water to make a total volume of 200 ml.