10.
已知:\(\rm{P_{4}(g)+6Cl_{2}(g)═4PCl_{3}(g)\triangle H=a}\) \(\rm{kJ⋅mol^{-1}}\),\(\rm{P_{4}(g)+10Cl_{2}(g)═4PCl_{5}(g)\triangle H=bkJ⋅mol^{-1}}\),\(\rm{P_{4}}\)具有正四面体结构,\(\rm{PCl_{5}}\)中\(\rm{P-Cl}\)键的键能为\(\rm{c}\) \(\rm{kJ⋅mol^{-1}}\),\(\rm{PCl_{3}}\)中\(\rm{P-Cl}\)键的键能为\(\rm{1.2c}\) \(\rm{kJ⋅mol^{-1}.}\)下列叙述正确的是\(\rm{(}\) \(\rm{)}\)