Stoichiometry Question

Question

Consider the following reaction: 2 Co_(s) + 3 H₂O_(g) → Co₂O_3(s) + 3 H_2(g). What mass of coblat (III) oxide will be produced if 7 grams of cobalt reacts with 8 grams of water vapour?

Answer 1

2Co + 3H₂O ==> Co₂O₃ + 3H₂ This reaction probably won't take place because Co is not very reactive, even with steam. But let us assume it does take place...

7 g Co x 1 mol Co/59 g x 1 mol Co₂O₃ / 2 mol Co x 166 g Co₂O₃/ mol = 9.8 g Co₂O₃

8 g H₂O x 1 mol H₂O / 18 g x 1 mol Co₂O₃ / 3 mol H₂O x 166 g Co₂O₃/mol = 25 g Co₂O₃

Co is limiting and the maximum mass of Co₂O₃ that can be produced is 9.8 g = 10 g (1 sig. fig.)