Two vessels divided by a partition cotain one mole of `N_(2)` and two moles of `O_(2)` gas. If the partition is removed and gases mixed isothermally, find the change in entrope due to mixing assuming initial and final pressure are same.

Explanation

Using
`DeltaS_(systm("mixing"))=-R sum n_(i) In z_(i)`
`=- R (1 xx In ((1)/(3)) +2 xx In((2)/(3)))`
`= - R (In 3+2 In((3)/(2)))`
`= 8.314 (1.0 +2 xx 0.4) = 15.9 J K^(-1)`