A) \[50.4\,J\,mo{{l}^{-1}}\]
B) \[8.4\,J\,mo{{l}^{-1}}\]
C) \[-50.4\,J\,mo{{l}^{-1}}\]
D) \[-8.4\,J\,mo{{l}^{-1}}\]
Correct Answer: B
Solution :
(i) \[AB(s)+aq\xrightarrow{{}}AB(aq),\] \[\Delta H=-21\,J\,mo{{l}^{-1}}\] (ii) \[AB(s)+x{{H}_{2}}O\xrightarrow{{}}AB\cdot x\,{{H}_{2}}O(s),\] \[\Delta H=-29.4\,J\,mo{{l}^{-1}}\] Aim: \[AB\cdot x{{H}_{2}}O(s)+aq\xrightarrow{{}}AB(aq),\] \[\Delta H=?\] Eq. (i) is equivalent to \[AB(s)+x{{H}_{2}}O\xrightarrow{{}}AB\cdot x{{H}_{2}}O(s),\] \[\Delta H=\Delta \,{{H}_{1}}\] \[AB\cdot x{{H}_{2}}O(s)+aq\xrightarrow{{}}AB(aq),\] \[\Delta H=\Delta {{H}_{2}}\] \[\Delta {{H}_{1}}+\Delta {{H}_{2}}=-\,21\] \[-29.4+\Delta {{H}_{2}}=-21\] or \[\Delta {{H}_{2}}=8.4\,J\,mo{{l}^{-1}}\]You need to login to perform this action.
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