Silanes are silicon hydrides of general formula Si _ n H _ 2 n +2 and have several applications. From the data given below, the bond dissociation enthalpy of Si - Si bond can be deduced as: H of the reaction 2 Si ( s )+3 H ₂( ~g ) Si ₂ H ₆( ~g ) is 80.3 ~kJ ~mol ⁻¹ Bond dissociation enthalpy for H - H =436 ~kJ / mol Bond dissociation enthalpy for Si-H = 304 ~kJ / mol f _H[ Si ( g )]=450 ~kJ / mol