Molarity = 0.100 mol / 0.250 mol dm3
= 0.100 mol / 0.250 dm3 * 1000 cm3/dm3
= 400 cm3
Volume (V) = Amount (n) / Concentration (C)
Given that the amount of HCl is 0.100 mol and the concentration of the solution is 0.250 mol/dm³, you can calculate the volume:
Volume (V) = 0.100 mol / 0.250 mol/dm³ = 0.4 dm³
Since 1 dm³ is equal to 1000 cm³, you can convert the volume from dm³ to cm³:
Volume (V) = 0.4 dm³ × 1000 cm³/dm³ = 400 cm³
Therefore, the volume of 0.100 mol of HCl in a 0.250 mol/dm³ solution is 400 cm³.