A container of volume 2L is seperated into equal compartments. In one compartment, one mole of an ideal monoatomic gas is filled at 1 bar pressure and the other compartment is completely evacuted. A pinhole is made in the seperator so gas expands to occupy full 2 L and heat is supplied to gas so that finally pressure of gas equals 1 bar. Then :

Options

A. `Delta U=Delta H= 150 J`
B. `Delta H= 250 J`
C. `Delta U= 100 J`
D. `Delta U=Delta H=0`

Answer

B

Explanation

Final temperature of gas must be double of the intial temperature
`Delta H= Delta U+Delta(PV)=nC_(v)DeltaT+Delta(PV) DeltaT=T_(f)-T_(i)=2T_(i)`
`=(nR)/((gamma-1))T_(i)+ Delta (PV)=(3)/(2)xx100+100=250J`