Step-by-step explanation:
As there are 1000 mL present in 1 L. So, 393 ml will be equal to 0.393 L. And, concentration of
present is 0.171 M.
As molarity is the number of moles present in liter of solution.
Molarity =

Therefore, putting the given values to calculate the number of moles as follows.
Molarity =

0.171 M =
no. of moles =
Thus, we can conclude that the number of moles of
formed are
.