Calculate the volume of 4.0m hydrochloric acid that is required to make 0.25m of the volume of 2.5dm of the solution

Your post could be improved to make a lot more sense. I assume you want to know what volume of 4.0 M(not m) is needed to make 2.5 dm^3 (not dm) of 0.25 M (not m).

dm^3 1 x M1 = dm^3 2 x M2
dm^3 x 4 = 2.5 dm^3 x 0.25

You need to understand the difference between m and M in chemistry. m stands for molality = mols solute/kg solution while M stands for molarity = mols solute/L of solution (or in your convention M = mols solute/dm^3 solution).

You teachers are rude. can you try to be helpful and NICER? because in a minute this is going to be a issue!

No offense btw

To calculate the volume of hydrochloric acid required, we need to use the formula:

C1V1 = C2V2

where C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume.

In this case, we are given:
C1 = 4.0 M (hydrochloric acid concentration)
C2 = 0.25 M (final concentration)
V2 = 2.5 dm³ (final volume)

To find V1, the initial volume of hydrochloric acid, we rearrange the formula as:

V1 = (C2 * V2) / C1

Plugging in the given values, we have:

V1 = (0.25 M * 2.5 dm³) / 4.0 M

Now, we need to convert the volume from dm³ to m³ to match the units of concentration. Recall that 1 dm³ is equal to 0.001 m³.

V1 = (0.25 M * 2.5 * 0.001 m³) / 4.0 M

Simplifying the equation:

V1 = 0.00625 m³ / 4.0 M

Finally, we can calculate the volume of hydrochloric acid:

V1 = 0.0015625 m³

Therefore, approximately 0.0016 m³ (or 1.6 liters) of hydrochloric acid is required to make a 0.25 M volume of 2.5 dm³ of the solution.