In a flask, colourless N2O4(g) is in equilibrium with brown coloured NO2(g). At equilibrium when the flask is heated to 100C, the brown colour deepens and on cooling it becomes coloured. Which statement is incorrect about this observation?
(a) The H for the reaction N2O4(g) 2NO2(g) is +ve
(b) Paramagnetism increases on cooling
(c) The H-U at 100C is equal to 200 cal
(d) Dimerisation is reduced on heating