1.40 M solution of 75.0 mL is diluted to a total volume = 278 mL. A 139-mL portion of that solution is diluted by mixing 117 mL of H2O. Determine the final concentration? (Assume the volumes are additive.)
using a sample of Ne gas of 30.1-g exerts a certain pressure in a container that has fixed volume. Determine What mass of Ar is needed to exert half the pressure (at the same conditions of volume and temperature)?