From first law of thermodynamics
`DeltaQ_(ABC) = DeltaU_(ABC) +W_(ABC)`
`W_(ABC) = W_(AB) +W_(BC) = 0 +nRT_(B) In (V_(C))/(V_(B)) = nRT_(B) In (2V_(0))/(V_(0))`
`= nRT_(B) In 2 = 2P_(0) V_(0) In2`
`DeltaU = nC_(v)DeltaT = (5)/(2) (2P_(0)V_(0) - P_(0)V_(0)) rArr DeltaQ_(ABC) = (5)/(2) P_(0)V_(0) +2P_(0)V_(0) In1`.