question_answer

            

The following two reactions are known                                           [AIPMT (M) 2010]

\[F{{e}_{2}}{{O}_{3}}(s)+3CO(g)\xrightarrow[{}]{{}}2Fe(s)+3C{{O}_{2}}(g);\]\[\Delta H=-26.8\,kJ\]

\[FeO(s)+CO(g)\xrightarrow[{}]{{}}Fe(s)+C{{O}_{2}}(g);\]\[\Delta H=-16.5\,kJ\]

The value of \[\Delta H\] for the following reaction

\[F{{e}_{2}}{{O}_{3}}(s)+CO(g)\xrightarrow[{}]{{}}2FeO(s)+C{{O}_{2}}(g)\]

A)  \[+10.3\,kJ\]          

B)       \[-\,43.3\,kJ\]

C)  \[-\,10.3\,kJ\]     

D)                   \[+\,6.2\,kJ\]

Correct Answer: D

Solution :

Given,

(I)

(II)

On multiplying Eq (II) with 2, we get

(III)

On subtracting Eq (III) from I, we get