The formula to calculate the mass (g) is:
\[ g = \frac{mmolL \cdot MW \cdot V}{1000} \]
Where:
Let's say the concentration is 5 mmol/L, the molecular weight is 180 g/mol, and the volume is 2 L. Using the formula:
\[ g = \frac{5 \cdot 180 \cdot 2}{1000} \]
We get:
\[ g = 1.8 \]
So, the mass (\( g \)) is 1.8 grams.