1. Tardigrade
  2. Question
  3. Chemistry
  4. Calculate Δ H in kJ for the following reaction C (g)+ O 2(g) longrightarrow CO 2(g) Given that, H 2 O (g)+ C (g) longrightarrow CO (g)+ H 2(g);Δ H=+131 kJ CO (g)+(1/2) O 2(g) longrightarrow CO 2(g);Δ H=-282 kJ H 2(g)+(1/2) O 2(g) longrightarrow H 2 O (g);Δ H=-242 kJ

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Q. Calculate $\Delta H$ in $kJ$ for the following reaction
$C (g)+ O _{2}(g) \longrightarrow CO _{2}(g)$
Given that,
$H _{2} O (g)+ C (g) \longrightarrow CO (g)+ H _{2}(g);\Delta H=+131 \,kJ$
$CO (g)+\frac{1}{2} O _{2}(g) \longrightarrow CO _{2}(g);\Delta H=-282 \,kJ$
$H _{2}(g)+\frac{1}{2} O _{2}(g) \longrightarrow H _{2} O (g);\Delta H=-242 \,kJ$

EAMCETEAMCET 2008

Solution:

Given, $H _{2} O (g)+ C (g) \longrightarrow CO (g)+ H _{2}(g);\Delta H=131 \,kJ \,\,\,\ldots (i) $

$CO (g)+\frac{1}{2} O _{2}(g) \longrightarrow CO _{2}(g) ;\Delta H=-282 \,kJ \,\,\,\ldots (ii)$

$ H _{2}(g)+\frac{1}{2} O _{2}(g) \longrightarrow H _{2} O (g) ; \Delta H=-242\, kJ\,\,\, \ldots (iii)$

$C (g)+ O _{2}(g) \longrightarrow CO _{2}(g) ; \Delta H=?\,\,\, \ldots( iv )$

On adding Eqs (i), (ii) and (iii), we get Eq (iv)

$ H _{2} O (g)+ C (g) \longrightarrow CO (g)+ H _{2}(g) ; \Delta H=+131\, kJ $

$CO (g)+\frac{1}{2} O _{2}(g) \longrightarrow CO _{2}(g); \Delta H =-282 \,kJ $

$H _{2}(g)+\frac{1}{2} O _{2}(g) \longrightarrow H _{2} O (g);\Delta H=-242\, kJ$

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$ C (g)+ O _{2}(g) \longrightarrow CO _{2}(g) $

$ \Delta H =(131-282-242)\, kJ =-393\, kJ $