Question: What volume of 2.5 M NaOH solution is required to prepare 2.0 liters a 0.75M NaOH?

Answer: To solve this problem, we can use the formula:

```

M1 * V1 = M2 * V2

```

Where M1 is the initial concentration, V1 is the initial volume, M2 is the final concentration, and V2 is the final volume.

We are given the following information:

M1 = 2.5 M

V2 = 2.0 L

M2 = 0.75 M

We need to find V1, which is the volume of the 2.5 M NaOH solution required.

```

2.5 M * V1 = 0.75 M * 2.0 L

V1 = (0.75 M * 2.0 L) / 2.5 M

V1 = 0.6 L

```

Therefore, 0.6 L of the 2.5 M NaOH solution is required to prepare 2.0 liters a 0.75M NaOH solution.