You have a 1.0 M stock solution of H2SO4 in a large flask. You need to dilute this to make a 0.25M solution of H2SO4 for an experiment. If you need exactly 100.0mL of the diluted solution, how would you make the diluted solution?

c1v1 = c2v2

1.0M x v1 mL = 0.25M x 100 mL
v1 = mL of the 1.0 M stuff. Add to 100 mL volumetric flask and make to the mark with distilled water. Mix thoroughly.

To make a 0.25 M solution of H2SO4 from a 1.0 M stock solution, you will need to dilute the stock solution with a solvent such as water. Here's how you can do it:

1. Calculate the volume of the concentrated stock solution you need to make the desired 0.25 M solution. You can use the formula:

(C1)(V1) = (C2)(V2)

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

Plug in the known values:
C1 = 1.0 M
V1 = unknown (let's call it x mL)
C2 = 0.25 M
V2 = 100.0 mL

Solve for V1:
(1.0 M)(x mL) = (0.25 M)(100.0 mL)
x mL = (0.25 M)(100.0 mL) / 1.0 M
x mL = 25.0 mL

Therefore, you need 25.0 mL of the 1.0 M stock solution.

2. Measure 25.0 mL of the 1.0 M stock solution using a graduated cylinder or pipette.

3. Transfer the measured amount of the stock solution into a clean, empty flask.

4. Add a suitable amount of the solvent (water) to the flask to bring the total volume up to 100.0 mL. The solvent volume can be calculated by subtracting the volume of the stock solution from the desired volume:

Volume of solvent = Desired volume - Volume of stock solution
= 100.0 mL - 25.0 mL
= 75.0 mL

Therefore, you need to add 75.0 mL of water to the flask.

5. Mix the contents of the flask thoroughly by gently swirling or inverting the flask several times.

6. The resulting solution will now have a concentration of 0.25 M H2SO4, and you can use it for your experiment.

Remember to handle concentrated solutions with care, as they can be hazardous. It's also important to use precise measuring equipment and follow proper lab safety protocols while performing this dilution.