问题详情

水的三相点附近，其汽化热和熔化热分别为44.82kJ·mol^-1和5.99kJ·mol^-1。则在三相点附近冰的升华热约为  (  )

  A．38.33kJ·mol^-1  B．50.81kJ·mol^-1

  C．-38.33kJ·mol^-1  D．-50.81kJ·mol^-1