Q54. The heat of combustion of solid benzoic acid at constant volume is - 321.30 kJ at $27 ^ { \circ } \mathrm { C }$. The heat of combustion at constant pressure is $( - 321.30 - x \mathrm { R } ) \mathrm { kJ }$, the value of $x$ is $\_\_\_\_$ .
Q54. The heat of combustion of solid benzoic acid at constant volume is - 321.30 kJ at $27 ^ { \circ } \mathrm { C }$. The heat of combustion at constant pressure is $( - 321.30 - x \mathrm { R } ) \mathrm { kJ }$, the value of $x$ is $\_\_\_\_$ .