Determine which of the following reactions at constant pressure represent surrounding that do work on the system environment :
(P) `4NH_(3)(g) + 7O_(2)(g) to 4 NO_(2)+ 6H_(2)O(g)`
(Q) `CO.O(g)+ 2H_(2)(g) to CH_(3)OH(l)`
(R) `C("s,graphite")+H_(2)O(g) to CO(g)+H_(2)(g)`
(S) `H_(2)O(s) to H_(2)O(l)`

Options

A. III,IV
B. II and III
C. II,IV
D. I and II,IV

Answer

D