The mea sured enthalpy change for burning ketene (ch2co) ch2co(g) 1 2 o2(g)88n 2 co2(g) 1 h2o(g) is dh1 5 2981.1 kj at 25°c. the enthalpy change for burning methane ch4(g) 1 2 o2(g)88n co2(g) 1 2 h2o(g) is dh2 5 2802.3 kj at 25°c. calculate the enthalpy change at 25°c for the reaction 2 ch4(g) 1 2 o2(g)88n ch2co(g) 1 3 h2o(g)

Answer : The value of enthalpy change for the reaction is, 2623.5 kJ

Explanation :

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

The given main reaction is,

The intermediate balanced chemical reaction will be,

(1)    

(2)    

Now we will reverse the reaction 1, multiplying reaction 2 by 2 and then adding all the equations, we get :

(1)    

(2)    

The expression for enthalpy of change will be,

Therefore, the value of enthalpy change for the reaction is, 2623.5 kJ

14,16 18 reacts with group