For the reaction C₂H₆ $$ \to $$ C₂H₄ + H₂

the reaction enthalpy $$\Delta$$_rH = __________ kJ mol^$$-$$1. (Round off to the Nearest Integer).

[ Given : Bond enthalpies in kJ mol^$$-$$1 : C-C : 347, C = C : 611; C-H : 414, H-H : 436 ]

__________ grams of 3-Hydroxy propanal (MW = 74) must be dehydrated to produce 7.8 g of acrolein (MW = 56) (C₃H₄O) if the percentage yield is 64. (Round off to the Nearest Integer).

[Given : Atomic masses : C : 12.0 u, H : 1.0 u, O : 16.0 u ]

A reaction of 0.1 mole of Benzylamine with bromomethane gave 23 g of Benzyl trimethyl ammonium bromide. The number of moles of bromomethane consumed in this reaction are n $$\times$$ 10^$$-$$1, when n = __________. (Round off to the Nearest Integer).

(Given : Atomic masses : C : 12.0 u, H : 1.0 u, N : 14.0 u, Br : 80.0 u]

The total number of unpaired electrons present in the complex K₃[Cr(oxalate)₃] is _____________.