Q11 of 62 Page 68

Consider the reactions given below. On the basis of these reactions find out which of the algebric relations given in options (I) to (iv) is correct?

(a) C (g) + 4 H (g) → CH4 (g); ΔrH = x kJ mol–1


(b) C (graphite, s) + 2H2 (g) → CH4 (g); ΔrH = y kJ mol–1


Reason: Same bonds are formed in both the reaction but in the second reaction there is breaking of bond take place in which energy is absorbed.

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On the basis of thermochemical equations (a), (b) and (c), find out which of the algebric relationships given in options (I) to (iv) is correct.

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