First, let's calculate the concentration by gram per liter:
C = [tex] \frac{19.3}{0.25} [/tex] = 77.2 g/L
Now, let's convert it to molarity, knowing that the molar mass of sodium chloride is 58.5g/mol:
Molarity = [tex] \frac{77.2}{58.5} [/tex] = 1.31 M
For more explanation:
molarity = [tex] \frac{gram}{Liter} [/tex] * [tex] \frac{Mol}{gram} [/tex] = [tex] \frac{mol}{Liter} [/tex]