# How many grams are there in .5 mol of CF_2Cl_2?

So what is the molecular weight of 1 mol of this material? Sum up the individual atomic masses, $C , F , C l , \left(12.011 + 2 \times 19. \ldots \ldots\right) \cdot g \cdot m o {l}^{-} 1$, and then halve this for your answer.