Cyanamide (NH_2CN) is completely burnt in excess oxygen in a bomb calorimeter, DeltaU was found to be -742.7 "kJ mol"^(-1), calculate the enthalpy change of the reaction at 298K. NH_2CN_((s))+3//2O_(2(g)) to N_(2(g)) + CO_(2(g)) +H_2O_((l)) DeltaH =?

Cyanamide (NH_2CN) is completely burnt in excess oxygen in a bomb calo

1.	Cyanamide (NH_2CN) is completely burnt in excess oxygen in a bomb calorimeter, DeltaU was found to be -742.7 "kJ mol"^(-1), calculate the enthalpy change of the reaction at 298K. NH_2CN_((s))+3//2O_(2(g)) to N_(2(g)) + CO_(2(g)) +H_2O_((l)) DeltaH =?
Answer» SOLUTION :Given: T=298 K , `DeltaU=-742.4 "kJ mol"^(-1)` `DeltaH`=? `DeltaH=DeltaU+Deltan_g RT` `DeltaH=DeltaU+(n_p-n_r)RT` `DeltaH=-742.4 +(2-3/2)xx8.314xx10^(-3)xx298` `=-742.4+(0.5xx8.314xx10^(-3)xx298)` =-742.4+1.24 `=-741.16 "kJ mol"^(-1)`