Question

the entanlpy of formation of

methane Co2 and H20 are- 17.9 kcal,
-94kcal and- 68.4 Kcal calculate the
enthalpy
combustion of methane at ordinary temperature ​

Answer 1

Answer:

Explanation:

The required equation for the combustion of methane is:

CH  

4

​  

+2O  

2

​  

⟶CO  

2

​  

+2H  

2

​  

O;ΔH=?

ΔH  

=ΔH  

f(products)

​  

−ΔH  

f(reactants)

​  

 

        =[ΔH  

(CO  

2

​  

)

​  

+2×ΔH  

(H  

2

​  

O)

​  

]−[ΔH  

(CH  

4

​  

)

​  

+2×ΔH  

(O  

2

​  

)

​  

]

        =[(−398.8)−2×241.6]−[(−76.2)−2×0]=−805.8 kJmol  

−1

 

Heat evolved by burning 22.4 litre (1 mole) methane=−805.8 kJ.

So, heat evolved by burning 1000 litre (1 m  

3

) methane=  

22.4

805.8

​  

×1000=−35973.2 kJ