The 1980s saw reports of fH (SiH2) ranging from 243 to 289 k] mol-1. For example, the

The 1980s saw reports of ∆fHΘ (SiH2) ranging from 243 to 289 k] mol-1. For example, the lower value was cited in the review article by R. Walsh (Ace.
Chem. Res. 14,246 (1981)); Walsh later leant towards the upper end of the range (H.M. Frey, R. Walsh, and LM. Watts, J Chem. Soc., Chem.
Commun. 1189 (1986)) the higher value was reported in S.-K.
Shin and J.L. Beauchamp, f. Phys. Chem 90, 1507 (1986) If the standard enthalpy of formation is uncertain by this amount, by what factor is the equilibrium constant for the formation of SiH2, from its elements uncertain at (a) 298 K, (b) 700K?