Tin (II) fluoride, SnF2, is found in some toothpastes. Tin (II) fluoride is made by reacting solid tin with hydrogen fluoride according to the following BALANCED equation. Sn (s) + 2 HF (g) → SnF2 (s) + H2(g) How many grams of hydrogen gas will be produced if 3.9 moles of tin react?