Answer:
The new concentration is 0,13 M.
Step-by-step explanation:
A dilution consists of the decrease of concentration of a substance in a solution (the higher the volume of the solvent, the lower the concentration).
We use the formula for dilutions:
C1 x V1 = C2 x V2
C2= (C1 x V1)/ V2
C2= (0,40 M x 1,0 L)/ 3,0L
C2= 0,13 M