The correct options are
A Work done by gas is RTo
C Heat absorbed by gas is 112RTo
Work done by gas for AB = Area under the line AB = Po(2Vo−Vo)=PoVo
For 1 mole of an ideal gas, PoVo=RTo
Work done by gas for process BC = 0 (∵ Volume is constant)
Therefore, work done by gas for ABC = Work done by gas for AB + Work done by gas for BC
Thus, total work done = RTo
Internal energy change for ABC can be calculated by adding the internal energy change for AB and BC or directly between A and C because internal energy is point function which depends on final and initial state.
Thus, internal energy change for AC,
ΔU=nCvdt=nCv(TC−TA)
For an ideal monoatomic gas,
Cv=32R
Now AB is a constant pressure process, thus
V∝T
∴VBVA=TBTA
Now VB=2Vo, VA=Vo and TA=To
⇒TB=2To
Now BC is a constant volume process, thus
P∝T
∴PCPB=TCTB
Now PB=Po, PC=2Po and TB=2To
⇒TC=4To
Thus, internal energy for ABC,
ΔU=nCv(TC−TA)
ΔU=1×32R(4To−To)=92RTo
Since Q=U+W
For ABC, Q=92RTo+RTo=112RTo