Answer:
0.558 M
Step-by-step explanation:
Data obtained from the question. This includes the following:
Initial concentration (C1) =..?
Initial volume (V1) = 25mL
Final volume = 25 + 50 = 75mL
Final concentration (C2) = 0.186 M
The initial concentration of the solution can be obtained as follow:
C1V1 = C2V2
C1 x 25 = 0.186 x 75
Divide both side by 25
C1 = (0.186 x 75) /25
C1 = 0.558 M
Therefore, the initial concentration of the stock was 0.558 M