The standard heat of formation of NO_(2)(g) and N_(2)O_(4)(g) are 8.0 and 2.0kcal mol^(-1) respectively . The heat of dimerization ofNO_(2) in kcal is

The standard heat of formation of NO_(2)(g) and N_(2)O_(4)(g) are 8.0

1.	The standard heat of formation of NO_(2)(g) and N_(2)O_(4)(g) are 8.0 and 2.0kcal mol^(-1) respectively . The heat of dimerization ofNO_(2) in kcal is
Answer» `10.0` `- 6.0 ` ` + 14.0` `- 14.0` Solution :`(1)/(2) N_(2)+O_(2) rarr NO_(2), DeltaH = 8 kcal`...(i) `N_(2)+ 2O_(2) rarr N_(2)O_(4), DeltaH=2kcal` ....(II) Aim `: 2NO_(2) rarrN_(2)O_(4) , DeltaH=?` Eqn. (ii) `- 2 XX `Eqn. (i) gives `0= N_92)O_94) - 2NO_(2)`or `2NO_(2) rarr N_(2)O_(4), DeltaH= 2-2(8)= -14.0 kcal`