Answer
Please see the work below.
Work Step by Step
We know that
$M_1V_1=M_2V_2$
Where $M_1$ is the concentration of the original solution and $V_1$ is the volume of the original solution. $M_2$ and $V_2$ are the concentration and final volume of the diluted solution, respectively.
We plug in the known values into the above equation to obtain:
$1L\times 0.646M=2.00M\times V_2$
$V_2=0.323L=323 \space mL$
