A) \[-574\text{ }kJ\,mo{{l}^{-1}}\]
B) \[-287\,kJ\,mo{{l}^{-1}}\]
C) \[+574\text{ }kJ\,mo{{l}^{-1}}\]
D) \[+287kJ\,mo{{l}^{-1}}\]
Correct Answer: B
Solution :
[b] The two equation are: \[\frac{4}{3}Al(s)+{{O}_{2}}(g)\to \frac{2}{3}A{{l}_{2}}{{O}_{3}}(s),\] \[{{\Delta }_{f}}G{}^\circ =-827kJ\,mo{{l}^{-1}}\] .... (1) \[\frac{4}{3}Cr(s)+{{O}_{2}}(g)\to \frac{2}{3}C{{r}_{2}}{{O}_{3}}(s),\] \[{{\Delta }_{f}}G{}^\circ =-540kJ\,mo{{l}^{-1}}\] .... (2) Subtracting equation (ii) from equation (i) we have, \[\frac{4}{3}Al(s)+\frac{2}{3}C{{r}_{2}}{{O}_{3}}(s),\to \frac{2}{3}A{{l}_{2}}{{O}_{3}}(s)+\frac{4}{3}Cr(s),\] \[{{\Delta }_{r}}{{G}^{{}^\circ }}=-287kJ\text{ }mo{{l}^{-1}}\]You need to login to perform this action.
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