Question

Consider the equations below.

Answer 1

Answer: Thus the overall equation will be $H_2+C_2H_4\rightarrow C_2H_6$

Explanation:

According to Hess’s law , the heat absorbed or evolved in a given chemical equation is the same whether the process occurs in one step or several steps.

According to this law, the chemical equation can be treated as ordinary algebraic expression and can be added or subtracted to yield the required equation. That means the enthalpy change of the overall reaction is the sum of the enthalpy changes of the intermediate reactions.

The intermediate balanced chemical reaction are:

(1) $H_2\rightarrow 2H^.$    

(2) $C_2H_4+H^.\rightarrow C_2H_5$  

(3) $C_2H_5+H^.\rightarrow C_2H_6$  

Now adding all the equations, we get :

$H_2+C_2H_4\rightarrow C_2H_6$

Thus the overall equation will be $H_2+C_2H_4\rightarrow C_2H_6$