Molar mass 496.4200 g/mol
Number of moles:
40 g x 1 mol / 496.4200 => 0.08057 moles
Volume in liters:
250.0 mL / 1000 => 0.25 L
Therefore:
M = moles / V
M = 0.08057 / 0.25
= 0.32228 M
hope this helps!
By using the following formula we can calculate the volume;
C₁V₁ = C₂V₂
C₁ = concentration of starting solution = 1.0m
V₁ = volume of starting solution that is needed to make the dilution = ?
C₂ = Desired concentration of final solution = 0.1m
V₂ = desired volume of final solution = 250ml
Now putting the values in the formula;
1 x V₁ = 0.1 x 250
V₁ = 25ml
Thus, the answer is 25ml.