Using standard molar entropy values, calculate delta standard molar entropy values for the following reactions. In each case account for the sign of delta standard molar entropy.
(a) C2H4(g) + H2(g) -> C2H6(g)
(b) N2O4 -> 2NO2(g)
(c) Be(OH)2(s) -> BeO(s) + H2O(g)
(d) 2CH3OH(g) + 3O2(g) ->2CO2(g) + 4H2O(g)