13. The mass of 3.75 mol of KF(s) is
a. 3.75 g
b. 58.1 g
c. 217.8 g
d. 108.9 g

C. 217.8 g

Explanation:

First, we find the weight of KF. notice they are 1:1 ratio. so the molar mass of K is 39.0983 and Fluorine is 18.998403

we add them together we get 58.09 g/mol

now to find the mass we do

* 3.175 mol

mol and mol cancel out, we left with 58.096 grams * 3.75

if you multiply you get 217.86 grams.