Answer:
the new concentration of the solution is 0.171 M.
Step-by-step explanation:
To solve this problem, we can use the formula for dilution:
C1V1 = C2V2
where C1 is the initial concentration, V1 is the initial volume, C2 is the final concentration, and V2 is the final volume.
Substituting the given values, we get:
(0.400 M)(300.0 mL) = C2(700.0 mL)
Solving for C2, we get:
C2 = (0.400 M)(300.0 mL) / (700.0 mL)
C2 = 0.171 M
Therefore, the new concentration of the solution is 0.171 M.