Question

How many liters of 8.0M `HCl` are needed to prepare 1.50 L of 2.5M `HCl`?

Answer 1

0.47 L of 8.0 M HCl are needed to prepare 1.50 L of 2.5 M HCl.

Explanation:

For dilution problems: `M_1V_1 = M_2V_2`, where `M_1` and `V_1` are the concentration and volume of the original solution and `M_2` and `V_2` are the concentration and volume of the diluted solution.

We are calculating `V_1`.

First rearrange the dilution equation:
`V_1 = (M_2V_2)/M_1`

Plug in the values:
`V_1 = ((2.5 M)(1.50 L))/(8.0 M)`

Calculate:
`V_1 = 0.47 L`