Question

If $\Delta H{{}_f}^0$ for $A{g}^{+}(\infty$ diluted), $NO{{}_3}^{-}(\infty$ diluted), $C{l}^{-}(\infty$ diluted) and $AgC{l}_{\left(S\right)}$ are $-105.579,-207.36,-167.159$ and $-127.068$ respectively. Calculate the enthalpy change for the reaction $AgN{O}_{3\left(aq\right)}+HC{l}_{\left(aq\right)}\to AgC{l}_{\left(S\right)}+HN{O}_3\left(aq\right)$.

• A. 21.471 kJ/mol
• B. 145.67 kJ/mol
• C. 65.488 kJ/mol
• D. None

Answer 1

The correct option is B 145.67 kJ/mol

$\Delta H_{reaction}^{\circ }=\left[\Delta H_f\right(AgCl)+\Delta H_f(H^{+})+\Delta H_f(NO{{}_3}^{-}\left)\right]$

$-\left[\Delta H_f^{\circ }\right(A{g}^{+})+\Delta H_f^{\circ }(NO{{}_3}^{-})+\Delta H_f^{\circ }(C{l}^{-})+\Delta H_f^{\circ }(H^{+}\left)\right]$

$\Delta H_{reaction}^{\circ }=-127.068-[-105.579-167.159]$

$\Delta H_{reaction}^{\circ }=145.67$ kJ/mol.