text: how many moles of nh3 are needed to react completely with 13.6 mol of f2? ammonia will react with fluorine to produce dinitrogen tetrafluoride and hydrogen fluoride 2nh3(g) + 5f2(g) → n2f4(g) + 6hf(g)  a.34.0 mol b.27.2 mol c.6.80 mol d.5.44 mol e.2.27 mol nh3 to f2 ratio is 2 to 5   that is you need 2 moles of nh3 to react with 5 moles of f2 2mol         5mol xmol         13.6mol --------------------------- use cross product, 2*13.6=5x, x comes out to be 5.44mol.