Two moles of an ideal monoatomic gas undergoes a process 1 - 2 - 3 as shown in figure.  Then total heat supplied to the gas in the process is

(4)Q12=Heat  supplied  in  the  process  1−2=2 ×  3R2×  2T0−T0=3RT0Process  2−3  is  isothermal.  Therefore  heat  supplied tothe  gas,  Q23=Work  done  by the  gas=P2V2  lnV3V2=nRT2ln V3V2  =  2.R.  2T0 lnV0V0∴  Q23 =  4RT0ln2∴    Total  heat  supplied  to  the  gas=Q12+Q23  = RT03+ln 16