Two moles of an ideal gas X and two moles of an ideal gas Y, initially at the same temperature and pressure, are mixed under isothermal-isobaric condition. The entropy change on mixing is ______________ $\mathrm{JK}^{-1}$. (Upto one decimal place, Use $\mathrm{R} = 8.31\ \mathrm{JK}^{-1}\ \mathrm{mol}^{-1}$)
Answer
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