For the reaction 2na(s) + cl2(g) --> 2nacl(s), how many grams of nacl could be produced from 20 l of cl2 (at stp)?

13.0 L Cl2 × 1 mol Cl2 /22.4 L Cl2 = 0.580 mol Cl2 103.0 g Na × 1 mol Na/23 g Na = 4.48 mol Na Cl 2 is limiting reagent: 0.580 mol Cl2 × 2 mol NaCl/1 mol Cl2 = 1.16 mol NaCl 1.16 mol NaCl × 58 g NaCl/1 mol NaCl = 67.3 g NaCl DIF: L3 REF: p. 371 OBJ: 12.3.1

You use the atomic number to find out how many protons and neutrons there are in the atom. you use the atomic mass to find out how many protons and electrons there are in the atom.