To calculate the mass of any given molecule, we usually need two informations: molar mass and number of mols.
In our case we have the number of mols, and the molar mass it is easily found online, for zinc thiocyanate for example is 181.5g/mol. Now we do the math:
181.5g = 1 mol
x grams = 7.9 moles
x = 1433.85 grams of Zn(SCN)2 or zinc thiocyanate