For the reaction shown, which is closest to the value of $\mathrm{\Delta }H$ ?

 

 

 

 

$2{\mathrm{Cr}}^{3+}\left(aq\right)+3\mathrm{Ni}\left(s\right)⟶2\mathrm{Cr}\left(s\right)+3{\mathrm{Ni}}^{2+}\left(aq\right)$

Given reaction is,

$2{\mathrm{Cr}}^{3+} + 3\mathrm{Ni} ⟶ 2\mathrm{Cr} + 3{\mathrm{Ni}}^{2+}$

$\mathrm{\Delta }{H}_f^{\circ }(-143\mathrm{kJ}/\mathrm{mol}) (-54\mathrm{kj}/\mathrm{mol})$

Here,

$\begin{array}{l}\mathrm{\Delta }H=\sum {\mathrm{\Delta }}_f{H}_p-\sum {\mathrm{\Delta }}_f{H}_R\\ =(3x-54)-(2x-143)\end{array}$

$-162+286\Rightarrow 124kJ$