3. In which reaction is the volume of the products equal to the volume of the
reactants?
A 2H2(g) + O2(g) → 2H2O(g)
B 3H2(g) + N2(g) → 2NH3(g)
C N2(g) + O2(g) → 2NO(g)
D 2502(g) + O2(g) → 2503(g)