Trihydrides, EH3 E N, P, As, Sb and Bi

Given that AfH (298K) for PH3(g) is +5.4kJmol calculate a value for the P—H bond enthalpy term in PH3. [Other data see Appendix 10.  

Construct an appropriate Hess cycle, bearing in mind that the P—H bond enthalpy term can be determined from the standard enthalpy of atomization of PH3(g). 

Standard enthalpies of atomization of the elements are listed in Appendix 10. 

Using data from Table 14.3 and Appendix 10, calculate a value 

Calculate a value for the Bi H bond enthalpy term in B1H3 using data from Table 14.4 and Appendix 10. 

Arsenic vapour contains AS4 molecules, and the unstable yellow form of solid As probably also contains these units. 

Name (lUPAC recommended) Ammonia Phosphine Arsine Stibine Bismuthane 

Name Ammonia (azane) Phosphane (phosphine) Arsane (arsine) Stibane (stibine) Bismuthane 

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