Answer:
117.5 g of SnFâ‚‚ can be produced
Explanation:
Let's think the reaction:
Reactants are Sn and HF. Therefore the products are SnFâ‚‚ and Hâ‚‚.
It is a redox reaction.
The equation is: Sn(s) + 2HF(g) → SnF₂(g) + H₂(g)
We convert the mass of the fluoride to moles
30 g . 1mol / 20g/mol = 1.5 moles of HF
By stoichiometry we produce 1 mol of SnFâ‚‚ with 2 moles of HF. Let's make a rule of three:
If 2 moles of HF can make 1 mol of SnFâ‚‚
Then, 1.5 moles of HF must produce (1.5 . 1) /2 = 0.75 moles of SnFâ‚‚
We convert the moles to mass  →  0.75 mol . 156.71 g /1mol = 117.5 g
