In an experiment carried out at 200�c and 1 atm pressure, 20 cm� of ammonia gas reacted with an excess of heated copper(ii)oxide. 3cuo (s) 2nh?(g) ?? 3cu(s) 3h?o(g) n?(g) If all measurements were made at 200�c and 1 atm pressure, what would be the total volume, in cm�, of gaseous products?

A. 10
B. 20
C. 30
D. 40